Unit- 2
Construction project planning
Construction project planning is the function in which project and construction managers and their key staff members prepares the master plan. Then this master plan is put into time schedule by scheduling people which is called project scheduling. A project plan is mostly responsible for the success or failure of the project.
Construction project planning and project scheduling is two separate and distinct function of the project management
2.1.1 Definition of Construction Planning
Planning is a bridge between the experiences of the past projects and the proposed actions that produces favorable results in the future. It can also be said that it is a precaution by which we can reduce undesirable effects or unexpected happenings and thereby eliminating confusion, waste, and loss of efficiency. Planning involves prior determination, specification of factors, forces, effects and relationships necessary to reach the desired goals.
2.1.2Types of Construction Project Planning
1. Strategic planning: this involves the high-level selection of the project objectives
2. Operational planning: this involves the detailed planning required to meet the strategic objectives
3. Scheduling: this puts the detailed operational plan on a time scale set by the strategic objectives.
6 basic project planning steps
The end result of every project planning process is a document or digital layout known as a project plan. Not only does this plan contain all the tasks and workflows required to reach your objectives, it will often include subsidiary plans for everything from budgeting to quality control.
To set your plan up for success, you should start by meeting with your manager, project sponsor, or key stakeholders to hammer out:
Clarifying these parameters upfront is paramount before you prepare the work breakdown structure for your project. Once you’re comfortable, you and your team can move on to the basic project planning steps below.
2.2.1. Create a schedule
To keep everyone involved on track and in scope, you’ll need to create a project schedule that:
Pro Tip: One of the best ways to keep all the information associated with your project intact, up-to-date, and accessible by everyone is with the help of a powerful planning tool like Mind Manager.
2.2.2 Line up your resources
Identifying and securing project resources in advance is essential for preventing missed deadlines. Those resources may include:
Your aim should be to assign a team member and/or resource to each project task.Pro Tip: You may need a separate plan for procuring resources that aren’t available in-house from third-party vendors, suppliers, or contractors.
2.2.3. Lay out a budget
All resources associated with your project – both human, and otherwise – are likely to have a cost attached to them. Your budget should break these amounts down in detail and project them through project completion.
2.2.4. Plan for quality
It’s important to establish quality criteria and targets so you’ll always know where your project stands relative to your goals. Consider using metrics to track and rank key deliverables, and having management sign off on each one.
Pro Tip: You may want to take advantage of project management software that makes it easy to view, update, and amend the status of time-critical tasks as needed.
2.2.5. Manage risk
Few projects are risk-free – even if the biggest threat is the possibility of a team member falling ill. Make sure you have a risk management plan in place to assess potential hurdles, and to provide contingency strategies to offset them.
2.2.6. Communicate your plan
You’ll need to design a communication strategy that keeps team members in the loop, and management and stakeholders up to date on your progress. Once your project plan has been mapped out in detail, it should be presented to everyone involved so oversights can be addressed and any changes can be approved before the plan is put into action.
Example 2 – Writing a book or web content
Collecting and conveying your ideas, knowledge, or expertise through a book, manual, or online content is time-consuming at best. At worst, it can be a process littered with missed deadlines.
Planning is the most critical component of any writing endeavor – and the only way to keep your project on track. The project planning process lets you get your ideas down visually, so you can:
Creating a project plan for your book also helps offset risk by making it easy to view and measure your progress against deadlines, while letting you pad out the timelines associated with submission dates.
Stage1-will always taken place after contractor received notice of tender which usually being advertised through electronic medium or convention medium that is through newspaper. Notice of tender also sometime being mailed to contractor by the parties who call for tender. This type of tender usually invited tender.
The duration taken for completion of this stage heavily depend on the following .
1. Types of tender: conventional, design and build or invited tender.
Size or value of project most of the time is confidential by the party who call foe tender.in Malaysia scenario the value of project will determine the category of contractor that can participate in the tender. Amount of information that needs to be disclosing by the tenderers.
In normal practice, the duration of the tendering process for Design and Build tender is from four (4) weeks to 3 months and usually it being break into two (2) stages which are prequalification stage and tender stage. The information that needs to be submitted during the tendering stage is the background of the contractor such as
1.Financial background
2.current background
3.previous experience
4.registration required under the conditions of prequalification.
5.Plant, machineries or equipment of the contractor.
6.Professional (qualified technical and administration) staff of the contractor
After screening by the party who call for tender, the contractor who pass the requirement of the prequalification will be notify and they are required to submit a complete tender document. This process is call prebidding stage or tender stage. At this stage, contractor will start to engage the following professional.
Design team to do the design for them.
1. Professional architect
2. Professional Civil Engineer
3. Professional structural engineer
4. Professional project management consultant
5. Professional mechanical engineer.
6. Professional electrical engineer
7. Professional quantity surveyor
The design team then will come out with the tender drawig or plan that will be submitted together with the tender document . The role of the project manager is to come out with the proposed work program with the help of all parties to feed him the relevant data in order for him to develop an almost accurate work program which then resulted to the duration of construction period that is needed to accomplish to work
Where as, for the Professional Quantity Surveyor will work on the builder cost inclusive of all preliminaries and generally item which then will be compiled to form a complete tender document.as for conventional tender contractor will only have to submit their pricing and background information. the background information is the same as the design and build prequalification stage .
Under the following pretender planning or management, in general it will involve the following stage.
1. Decision to participate in tender
2. Purchase of tender document
3. Pre tender meeting
4. Construction method
5. Cost Estimate stage
6. Pretender work program
7. Decision on overall tender pricing to be submitted and
8. Submission of the tender document
All of the information provided above is a good practice in pretender planning or management. In actual of fact, the above mention stages and information heavily depend on the organization it self. Different organization have different approach on how their pretender planning or management going to be. Some of the stages might no be necessary for small scale project which intended for small scale contractor which the owner himself could be able to do all the stages This mean that the above stages, especially the pre tender meeting is not required. Then this stage will not be applicable to them.
Contractor is a third party that needs to put most effort in planning. The results of contractor’s planning, monitoring and contract control will have a direct impact on the profit of the contract (Frank Harris, 2013). Planning is done from broad process making it more detailed. A project plan contains a Work Breakdown Structure, responsibility chart, schedule and additional documentation that describes budget (Robert B.Angus, 2003). To develop a detailed project plan from the preplanning phase. Then he has to build a work breakdown structure where the project has to be divided into smaller work packages. After all the project tasks are defined they have to be sequenced and each work package needs to be estimated in terms of duration, costs, labor skills and equipment requirements. After these estimations the project manager is able to calculate an initial schedule, where he can identify the critical path and establish milestones. He then also can assign and level the resources which after that leads to realistic project schedule and resource forecast. In the last step the project manager develops a budget and this finally leads to a project plan, with all project tasks, established schedule, responsibilities, resource forecast and budget.
2.4.1 Considerations before starting the estimations
The bidding period is the time between the announcement of the project and the availability of the contract and bidding documents to the contractor, and the time when the proposals have to be submitted to the owner. During this period the contractors have to carefully analyze all the tender material, prepare his costs estimations for the construction and prepare his proposal for the owner. The results of these estimations should provide the contractor with an overall idea of how much work the construction project requires. It is quite common that during the bidding period the contractors finds errors uncertainties or miss some information in the tender material. It is contractor’s responsibility to identify these flaws to the owner so that the suitable modifications could be made. (Richard H. Clough, 2015) After the owner informs the contractors about the project, the contractors have to examine the information in the advertisement or the invitation to bid. If the contractor decides is interested in the project, he will receive set of bidding documents from the owner of the designer. It is up to the contractor to make sure that all the contract documents are clear and sufficient. In tender material the owner may include pre-qualification criteria in order to eliminate inexperienced, incompetent or underfinanced contractors. The contractors’ decision to bid involves many factors that includes his opinion about the owner’s designer, size and nature of the project which is related to company’s experience, machinery requirements, project location, seasons, duration of the project, the bidding period, terms and conditions in the tender material, possible competition, resource requirements and other aspects. The decision to bid and preparation of the bidding proposal requires considerable amount of time, effort and money, therefore the contractor will always try to bid on the projects that he thinks he will be awarded. (Richard H. Clough, 2015)
2.4.2 Contractor’s team
The contractor is responsible for planning, managing and executing the building in accordance to project drawings, specifications and other contract documents. In order to help with these tasks, the owner can have number of people involved. The planners are responsible for producing the construction plans. These plans include task sequence and approximate resource requirements. The estimators are the people responsible for managing and making more precise estimates of the projects. These team members should have a good cooperation in order to prepare good pre-tender estimates. Buyers are responsible for material purchase and hiring sub-contractors. Temporary works-designers are responsible for major temporary works (i.e. scaffolding, bridge supports, falsework). Site managers are responsible for controlling the day-to-day operations on construction site. (Frank Harris, 2013)
2.4.3 Risk management
According to (Verzuh, 2008) the planning consists of two major components: risk management and schedule and budget development (see fig 3.6). Risk management and detailed planning are closely related to each other and can be repeated several times before the construction begins. With every review the project plan become more and more accurate.
A risk management is the process of forecasting and evaluating financial risks and identification of the procedures to avoid them or minimize their impact. All construction projects carry certain risks and these risks can be managed, minimized, shared, transferred or accepted. These risks face all participants involved in the construction project. Generally, risks determine the practical, financial and contractual relationships between the stakeholders. There are certain risks are involved in all the phases of construction project lifecycle. In order to deal with the risks, it is necessary to asses them. This involves risk identification, impact analysis, probability estimations and prioritization. In order to manage the risks well it is important to balance the costs and benefits of dealing with them.
2.4.4 Estimating
For the contractor estimating is part of planning process. In order to make estimates, a project plan of works is required. In order to prepare estimates, the contractor has to use information acquired from the tender documents. During the estimating process, the resources required for each activity are considered. Also the contractor identifies and allocates and calculates the costs for the work performed by sub-contractors. Estimations data is structured in accordance to the planning model. This is important because structured data later can be used for other purposes. Normally, in pretender estimations the units of work are expressed in weeks or days (Frank Harris, 2013). As stated by (Carmichael, 2006) according to the degree of accuracy the price estimations can be divided into three different stages: - Approximate (20-25% accuracy) estimations are used to evaluate size and duration of the project. - Preliminary (10-20% accuracy) estimations are calculated by estimating every part of work in the project. This price estimate is commonly used to decide whether to start with the project. Detailed (5-10% accuracy) estimations are used for tendering or re-planning purposes. This type of estimation requires either accurate unit rates or bottom up approach.
2.4.5 Defining and planning project scope
A project scope is the list of works that need to be done in order to meet the project objectives. The project scope statement is a tool for managing expectations and dealing with changes. In case of disagreements on the project they often can be resolved by reviewing the original agreement on statement of work (Verzuh, 2008). However, the original agreement can be changed during the project. In this case it is important that all the involved stakeholders understand and agree on those changes. After the changes are made they need to be included in project scope statement. Part of the project planning is defining a project scope. It involves defining and documenting a list of works that need to be done for completing the project. Project scope planning together with scope definition divides the project into different functions or sections. The project can be broken down to smaller parts which can be once again divided into even smaller parts where every lower level has a greater amount of details. This is called Work breakdown structure (WBS) and it is systematic decomposition of the work to be executed (Carmichael, 2006, s. 117). The WBS identifies all the tasks in the project and sometimes can be referred as a task list. Creating a WBS assists project manager in numerous ways. Through making a WBS a project manager gets detailed information about the project scope and the tasks on WBS can be used later as a basis to monitor the project progress. It also helps to calculate more accurate the costs for labor, equipment and materials for each task and help with more precise schedule estimates. WBS can be used to build the project teams, giving them clear work assignments
2.4.6 Managing the project scope
In construction industry a project scope is often referred as the design brief and is considered under the project definition (Fewings, 2005). It involves defining and documenting specific goals of the project, features, functions, tasks, deadlines and costs. The more is described during the design brief, the more it is possible to develop and improve it. Defining the scope can be time consuming process, especially if the stakeholders that contribution is needed are not available. Differences in understanding of what the client expectations are can lead to different understandings what is exactly required. That is why the project scope not only needs to be agreed in the early stages of the project but it also requires constant monitoring in order to avoid exceeding project budget, time overruns and conflicts with stakeholders’ expectations. For all the stakeholders to have a better understanding it is beneficial not only to define the things that are within the scope, but also the things that are out of the project scope. According to (Newton, 2015) most of experienced project managers agree that the project scope needs to be decided and documented before any actual work starts. Once the project scope is written and defined it can be negotiated and modified by the project stakeholders and once they formally agree to its’ contents it becomes an instruction for the project (Verzuh, 2008). Along with defining the project scope in the planning stage it is also important to actively manage it. This is because the stakeholders will try to make changes of the scope during the project lifecycle. According to (Newton, 2015) these stakeholders can be classified into two part Internal stakeholders: are the project team members. These stakeholders are usually under the direct control of the project manager. Their reason for scope changes involves professional pride and functional factors. - External stakeholders: includes project sponsors and end-users. The reason they want the changes in the project scope could be that not all their expectations were included in the initial project specification. They might be unaware that making additional changes during the execution phase can increase the risk and costs of the project. They might believe that these changes are relatively small but will add great value to the project.
2.4.7 Pre-construction meeting
A pre-construction meeting should be called after the owner chooses a contractor. The purpose of this meeting is to introduce the involved parties to the procedures that need to be followed through the development of the project. According to (American Society of Civil Engineers, 2012) the first preconstruction meeting is usually held by the owner. Depending on the type of contract after the owner’s pre-construction meeting, the similar meetings can be called by the main contractor, prime consultant or some other party. Regardless of who is calling the meeting, it is important that all important topics are covered. That can be achieved by proposing an agenda for the meeting, allowing participants to have their input on discussion topics (Hayes, 2013). According to (American Society of Civil Engineers, 2012) the agenda for these meetings should include the issues that needs to be resolved before construction of specific activity begins. Pre-construction meeting should include all the major stakeholders of the construction phase. Since the architect is in control of some essential administrative processes during construction (i.e. submittal approvals, determination of work conformance, etc.
Project Definition Rating Index (PDRI) is a method to measure the completeness of project scope definition, identifying gaps and taking right actions in order to reduce risk during the pre-planning phase. It is used during the multiple stages of the pre-planning process. The tool has included list of 64 elements that needs to be considered during the pre-planning process. The tool was developed by a research team formed by the Construction Industry Institute (CII) (Chung-Suk Cho, 2001). The tool uses scoring system where lower score represents a better scope definition. It is applicable to several floors as well as single story commercial, institutional, or other light industrial facilities. PDRI is an effective tool that can help owners, designers and contractors to assess the possibility to achieve the project objectives during pre-planning. Part of the project planning is to assign responsibilities for the various elements of the project. A responsibility matrix is a tool to list all the parties involved in the project and linking them to the tasks that needs to be completed. The responsibility matrix is a way to inform project stakeholders about their roles and duties. Creating this matrix can be time consuming, but the project manager can find it useful, since he can get a clear indication that is responsible for various tasks of the project. This helps to prevent misunderstandings about the task assignments and highlight the workload of every stakeholder involved in the project. Yet, the responsibility matrix can become quite complex for a very large projects.
2.5.1Task order
Construction planning and managing is focused on the right sequence and performance of the activities at construction site. The project planning phase consists of three stages (Richard H. Clough, 2015): - Identifying the tasks to be done in order to complete the project - Establishing order in which these tasks will be completed - Making a graphical activity network schedule Some tasks need to be performed before the others. That is sequence constraint and it is dependent on the relations between the different tasks. For example, the foundation has to be made before building the walls and covering the roof. The order of the tasks cannot be changed and they must follow the certain order. The activities that can be performed simultaneously are known as concurrent tasks .
2.5.2Calculating initial project schedule
Realistic schedule is part of the project success. It needs to be regularly updated during the preplanning phase and later also during the construction. During this process the project team increasingly includes greater amount of details about the activities for the sub-contractors and other involved parties.
2.5.3 Gantt charts
Gantt charts, also called as ‘bar charts’ (Carmichael, 2006) contains an information about the project activities and levels. It is a graphical picture displaying schedule information. On the horizontal axis the schedule is displayed, while the vertical axis lists the activities to be done. According to (Richard H. Clough, 2015) the main advantage of Gantt chart is the simplicity of its’ visual design which makes it very easy to understand. It provides a convenient way to monitor the work progress, check schedule and equipment, material deliveries and follow project advancement.
2.5.4 Establishing milestones
Expectations can provide clarity for the workers when they are involved in the project. According to (R. Duane Ireland, 2009) employees are more willing to accept more challenging expectations when they are clearly defined. Milestones are tools used by the project managers that can help to create a structure and clarity for employees. Established milestones set expectations for progress rate and objectives to achieve. Having pre-specified can determine time when stakeholders can discuss progress, compare it to pre-planned forecasts, unforeseen obstacles and other unforeseen changes that may influence the progress of the project.
2.5.5 Resource planning
Resources can be people, machinery and other matters that are required to carry out the project tasks. They are separated from finances that can be used to measure their usage. Resource planning is deciding about the usage of the resources on a project. Part of the resource planning is leveling the resources. The project manager can desire resource leveling to keep the workers at consistent and reasonable rate (Verzuh, 2008). Similar to that it is also not desirable to use the machinery intermediately. Smoothing the material usage helps to avoid possible shortages in supply during the peak time periods. Resource constraint scheduling is a planning method that resource requirements would not exceed the available quantity. Some of the resources can be expensive or limited quantity (i.e. crane, skilled workers). A schedule is not realistic if it requires excess of the available resources (Carmichael, 2006). Essentially, evening out the resources peaks leads to higher utilization and more efficient usage of the resources it also helps to avoid the situations where needed resources are not available.
2.5.6 Financial planning
Financial planning is related to every stakeholder who is involved into deciding how much money should be used on the project. The project budget is a detailed estimate of costs for all the activities and tasks required to complete the project. Initial project budget is based on the estimated project scope, effort, schedule and it represents expected costs over the life of the project. As the project is being executed the actual costs can be tracked and compared with preliminary estimated values. Changes in the project scope, resources costs fluctuations and other factors can negatively affect project costs. The designer can provide probable construction costs to the owner. Often the designer’s costs calculations are based on his experience with similar projects (American Society of Civil Engineers, 2012). In order to get more precise budget estimations, the owner can review the costs with a professional costs estimator and experienced contrac
The owner is the individual or organization for whom a project is to be built under a Contract. The owner owns and finances the project. Depending on the owners’
Capabilities, they may handle all or portions of planning, project management, design, Engineering, procurement, and construction. The owner engages architects, engineering Firms, and contractors as necessary to accomplish the desired work.
Public owners are public bodies of some kind ranging from agencies from the country
Level to the municipal level. Most public projects or facilities are built for public use and Not sold to others. Private owners may be individuals, partnerships, corporations. Most Private owners have facilities or projects built for their own use or to be sold, operated, Leased, or rented to others. In order to achieve success on a project, owners need to define accurately the projects Objectives. They need to establish a reasonable and balanced scope, budget, and schedule.
They need to select qualified designers, consultants, and contractors.
2.6.1 The Design Professionals
Examples of design professionals are architects, engineers, and design consultants. The Major role of the design professional is to interpret or assist the owner in developing the Project’s scope, budget, and schedule and to prepare construction documents. Depending On the size and sophistication of the owner, the design professional can be part of the Owner’s group or an independent, hired for the project. In some cases design professional And construction contractor together form a design-build company.
Architect: An architect is an individual who plans and design buildings and their
Associated landscaping. Architects mostly rely on consulting engineers for structural,
Electrical, and mechanical work.
Engineer: The term engineer usually refers to an individual or a firm engaged in the
Design or other work associated with the design or construction. Design engineers are Usually classified as civil, electrical, mechanical depending upon their specialty. There are also scheduling, estimating, cost, and construction engineers.
Engineering-Construction Firm: An engineering-construction firm is a type of
Organization the combines both architect/engineering and construction contracting. This Type of company has the ability of executing a complete design-build sequence.
2.6.2 The Construction Professionals
The constructions Professional are the parties that responsible for constructing the
Project. In traditional management where the owner, design professional, and contractors are separate companies, the contractor would be termed a prime contractor. The prime Contractor is responsible for delivering a complete project in accordance with the contract Documents. In most cases, the prime contractor divides the work among many specialty Contractors called subcontractors.
Contractor hierarchy
The Project Manager
The project manager is the individual charged with the overall coordination of the entire
Construction program for the owner. These include planning, design, procurement, and
Construction. Among his/her duties:
- Clear definitions of the goals of the project.
- Investigate alternative solutions for the problems.
- Develop a detailed plan to make the selected program reality.
- Implement the plan and control the project.
Construction Manager: The construction manager is a specialized firm or organization
Which administrates the on-site erection activities and the consulting services required by The owner from planning through design and construction to commissioning. The Construction manager is responsible for design coordination, proper selection of materials And methods of construction, contracts preparation for award, cost and scheduling Information and control.
A Work Breakdown Structure (WBS) is a breakdown of all the work that will go into completing a project. A WBS a way for you to build out a flowchart that breaks all of the deliverables down into manageable tasks and provide your team with a guide for developing a product or completing a project.
There are three general components that make up a work breakdown structure:
A clearly defined work breakdown structure allows you to make sure every detail and phase of a project is accounted for before you begin. It visually communicates the big picture, and helps everyone stay on the same page throughout the entire project.
When all of your deliverables are broken down into smaller tasks, it’s easier to establish dependencies and create a project timeline. You can also write a more detailed statement of work (SOW), which keeps the plan in scope and sets clear expectations for your team and stakeholders.
Since the work to be done is already defined and broken down into manageable pieces, your team can get to work immediately instead of waiting for instructions. They can be more productive, and you’re able to hold them accountable for the work they do.
Getting this kind of clarity at the beginning stages of a project will help you avoid being among the 25% of technology projects that fail outright, not to mention the 50% that need massive reworking by the time they’re finished.
Although you can make work breakdown structures by hand or in flowchart tools, it’s often time-consuming and isn’t easily updated. Using project management software to build a work breakdown structure keeps all the information up-to-date and gives your team clarity while you have the flexibility you need to plan work.
2.7.1 How to Create a Work Breakdown Structure
Following we have listed the steps you need to take to create a work breakdown structure from scratch.
Step 1: Get your team together to identify the deliverables and sub-deliverables of the project. This would include the project managers and the subject matter experts.
Step 2: Gather the necessary documents such as the project charter, project scope statement, and project scope management plan.
Step 3: Identify the key deliverables of the project. These should come at the second level of your WBS. Key deliverables will be essential to the completion of the project and they will be carried out by independent teams – meaning the same team won’t be working on completing another deliverable.
Step 4: With the help of the subject matter experts, break the key deliverables into smaller parts of work (work packages) or in other words identify the work that is necessary to complete each deliverable.
Step 5: Create a WBS dictionary which is a document that includes the definition and the scope of the different elements in your work breakdown structure. The WBS dictionary would include information such as work package name and ID, name of the person it is assigned to, due date, estimated cost, etc. This will help the team understand work packages better.
Step 6. You can create a WBS using different formats like text-based work breakdown structures, tabular structures, or more visual ones like flowcharts. Once it is complete, share it with the team. A Creately work breakdown structure can be quickly shared with the rest of your team with a secure share link – once shared, you can collaborate on it in real-time.
HOW TO CALCULAE WORK BREAKDOWN STRUCTURE
Activity list is a list of all schedule activities that are required on a project. That doesn’t really explain much though; does it?
Activities are the portions of work that must be performed to complete the project. They are the items that become sequenced for scheduling. They become estimated for budgeting.
The activity list is simply a place to log all of the activities. The list presents the activity number or identifier, the name of the activity, and a detailed description of the activity. The description should sufficiently describe the scope of work so that all project team members can understand exactly what must be performed. It also tracks the person(s) responsible for performing the work.
So where does it belong in the big picture? Typically, there are multiple activities in a work package, multiple work packages in a phase and multiple phases in a project.
Activities are the very smallest units of work. When decomposing items into activities, the best practice is to involve the team members who will be performing the project work.
This guide provides you with a step-by-step overview and everything you need to know for conducting the best project assessments. It includes key questions that you need to ask when analyzing a project and also references AGS Cloud’s best program assessment templates & samples
How to Perform Your Project/Program Assessment
Follow the steps below to conduct your project assessment:
Productivity refers to the physical relationship between the quantity produced (output) and the quantity of resources used in the course of production (input). “It is the ratio between the output of goods and services and the input of resources consumed in the process of production.”
Output implies total production while input means land, labour, capital, management, etc. Productivity measures the efficiency of the production system. The efficiency with which resources are utilized is called productive efficiency. Higher productivity means producing more from a given amount of inputs or producing a given amount with lesser inputs.
At the level of a plant or an industry productivity is an output-input ratio. But at the macro level, productivity is a measure of performance of an economy or country. From a nation’s viewpoint productivity is the ratio of available goods and services to the potential resources of the country.
Productivity means an economic measure of output per unit of input. Output refers to the total production in terms of units or in terms of revenues while input refers to all the factors of production used like capital, lab our, equipment, etc. Productivity is a good indicator of the efficiency with which a factory is operating. If a firm has higher productivity, i.e. it produces more with a given amount of inputs, it means it is utilizing the resources properly.
Productivity can be calculated as the ratio of the volume of output to the volume of inputs.
Productivity = Output/Input
Productivity can be increased by:
i. Generating more outputs from same level of inputs.
ii. Producing same level of outputs with reduced level of inputs.
iii. A combination of both.
The concept of productivity can be applicable to any economy, small, medium and large business, government and individuals. Productivity aims at the maximum utilization of resources for yielding as many goods and services as possible, desired by consumers at lowest possible cost. Productivity is the ratio of output in a period of time to the input in the same period time.
2.10.1 Productivity can measured with the help of following formula:
In simple terms Productivity is the ratio of output to some or all of the resources used to produce the output.
Productivity – Importance
Productivity has become almost synonymous for progress. The resources of a country are generally limited. Therefore, higher productivity is essential for improving living standards and for the prosperity of a nation. Higher productivity requires elimination of waste in all forms. Higher productivity leads to economic growth and social progress.
Aspiring project managers must learn how to perform a variety of tasks in order to get a project started and estimating activity duration is one of them. It’s not always an easy task to estimate the project duration, because doing so needs a Project Manager’s knowledge of some theory, along with the application of some best practices and methodologies.
To estimate activity duration is a lengthy process and it takes time for a long-term project. Ideally, you should involve your core project team in estimating the duration. You should involve the project team, who will work on the project to achieve the project objectives, project management team, and all the identified key stakeholders to make a consensus on the milestone dates, and delivery schedules. Depending on this duration, you can develop a schedule, with milestones for your project.
Estimating activity duration can be for a project phase or product phase and is iterative in nature. It can be changed as work progresses and as new activities identified in your project. Initially, you can estimate your project based on the network diagram (sequencing the activities). It can be further modified based on the changes done in the project during the execution, controlling and monitoring the process.
The PMI recommends a few project management tools, methodologies, best practices for estimating the duration. They are as follows:
Analogous Estimating
This is a very important methodology that gives you the entire duration estimation. Based on the information on past projects that are similar, you can get a ballpark idea of the entire duration estimation. You may be able to get this information from the Project Management Office or another project manager; you can use this template for your current project.
Analogous estimating the activity duration is not so accurate in nature; however, it is less costly and less time consuming than other methods. You can frequently use this method when you don’t have sufficient time to do a proper estimate, and you have a deadline. Analogous estimating can be of a part of the project as well since you don’t have to estimate the entire project. You can estimate activity duration for a single phase of the project if the requirement /nature of the phase is very similar to the previous processed project.
Parametric Estimating
This method is more accurate in nature. It is based on a statistical calculation of historical data and other variables. For example, in the design phase in case of a construction project, you may already have the activity duration: cutting 1,000 stones will take 8 hours and so on. If your project is of a similar nature to one performed in the past, it is worth your while to find existing activity duration estimates and historical data from the past project.
Aspiring project managers must learn how to perform a variety of tasks in order to get a project started and estimating activity duration is one of them. It’s not always an easy task to estimate the project duration, because doing so needs a Project Manager’s knowledge of some theory, along with the application of some best practices and methodologies.
To estimate activity duration is a lengthy process and it takes time for a long-term project. Ideally, you should involve your core project team in estimating the duration. You should involve the project team, who will work on the project to achieve the project objectives, project management team, and all the identified key stakeholders to make a consensus on the milestone dates, and delivery schedules. Depending on this duration, you can develop a schedule, with milestones for your project.
Estimating activity duration can be for a project phase or product phase and is iterative in nature. It can be changed as work progresses and as new activities identified in your project. Initially, you can estimate your project based on the network diagram (sequencing the activities). It can be further modified based on the changes done in the project during the execution, controlling and monitoring the process.
The PMI® recommends a few project managements tools, methodologies, best practices for estimating the duration. They are as follows:
2.11.1 Analogous Estimating
This is a very important methodology that gives you the entire duration estimation. Based on the information on past projects that are similar, you can get a ballpark idea of the entire duration estimation. You may be able to get this information from the Project Management Office or another project manager; you can use this template for your current project.
Analogous estimating the activity duration is not so accurate in nature; however, it is less costly and less time consuming than other methods. You can frequently use this method when you don’t have sufficient time to do a proper estimate, and you have a deadline. Analogous estimating can be of a part of the project as well since you don’t have to estimate the entire project. You can estimate activity duration for a single phase of the project if the requirement /nature of the phase is very similar to the previous processed project.
2.11.2 Parametric Estimating
This method is more accurate in nature. It is based on a statistical calculation of historical data and other variables. For example, in the design phase in case of a construction project, you may already have the activity duration: cutting 1,000 stones will take 8 hours and so on. If your project is of a similar nature to one performed in the past, it is worth your while to find existing activity duration estimates and historical data from the past project.
2.11.3 Three-Point Estimating
This kind of estimate is based on considering various options like the assignment of the resources, uncertainty, and the risk associated—such as best scenario-based and worst-scenario based. The three-point estimating concept is originated from the PERT (Program Evaluation and Review Technique). Through PERT, we generally estimate three types of duration:
Of these, Most Likely (M) is based on the resources assigned and Optimistic (O) is based on the best scenario-based analysis. And the last one—Pessimistic (P)—is based on the worst possible scenario-based analysis. Once you have these, you can use some very useful formulas to derive the expected duration. They are as follows:
TE = (O + 4M + P) ÷ 6
Here, TE is expected time, and O, M, P are Optimistic, Most Likely, and Pessimistic duration respectively. In this way, you can understand the importance of PERT in estimating the duration of your project.
2.11.4 Heuristic Estimating
This is also known as Rule of Thumb. You can roughly guess that the entire design phase can take 45% off your entire project time and so on…this is a very useful technique in case of known phases where you can put an imaginary figure based on the experience.
2.11.5 Reserve Analysis
Reserve analysis is a type of contingency reserve. After fixing a schedule for each activity level depending on the activity attributes, you can create contingency reserve timing by adding some percentage in the derived schedule of each activity. It can be changed as work progresses; reducing or increasing depending on the situation.
Sequence of activity Sequence activities is the process of identifying and documenting relationships among the project activities. In the project management, the key benefit of this type of process is that it defines the logical sequence of work to obtain the greatest efficiency given all project constraints.
In the project management process groups and knowledge area mapping the sequence activities fall under the planning process group and project time management knowledge areas. The project schedule development uses the outputs from the processes to define activities, sequence activities, estimate activity resources, and estimate activity durations in combination with the scheduling tool to produce the schedule model.
In the sequence activities data flow diagram, every activity and milestone except the first and last should be connected to at least one predecessor with a finish-to-start logical relationship and at least one successor with the finish-to-start or finish-to-finish logical relationship. Sequencing can be performed by using project management software or by using manual or automated techniques.
Moreover, the schedule management plan identifies the scheduling method and tool to be used for the project, which will guide how the activities may be sequenced.
This term is defined in the 5th edition of the PMBOK.
Many different methods for planning exist, each with their own benefits and drawbacks in different situations. No one technique will be suitable for every situation, in fact, a number of these techniques will usually be required for a successful overall strategy. Different methods are used to cover different timeframes, areas of the business and utilize different skill-sets.
Many different methods for planning exist, each with their own benefits and drawbacks in different situations. No one technique will be suitable for every situation, in fact, a number of these techniques will usually be required for a successful overall strategy. Different methods are used to cover different timeframes, areas of the business and utilise different skill-sets.
2.12.1 Strategic Planning
Strategic planning aims to ensure employees and other stakeholders are all working towards a common goal and their energy, focus and resources are all aligned towards this. Agreements are made about the direction the organisation wants to move in and how every contributor can ensure this happens. As well as the overall goal and how they are going to get there, a strategic plan also often lays out how the success of the strategy will finally be measured.
2.12.2 Action Planning
Unlike strategic planning, this type of planning is far more focused on day-to-day activities. Individual, team or project activities are organised and set out in a timetable. This helps to focus attention on the task at hand, rather than focusing on the bigger picture. This increases levels of motivation and efficiency, as well as providing a useful tool for monitoring and evaluation after the task has been completed. Specific details are planned for to the level of who will be where, when and the exact amount of resources they will require.
2.12.3 Tactical Planning
This type of planning builds on the strategic plan already set out, by breaking the tasks down into short-term actions and plans. It is usually drawn up by lower-level managers as they have better knowledge of their departments and day-to-day running of the business. The extra level of detail in a tactical plan increases efficiency and helps individuals and teams to know exactly what is required of them.
2.12.4 Operational Planning
This type of planning aligns different functions of the business, for example HR or marketing, with the overall goals and objectives of an organisation. This includes planning levels of resources, processes, where people are needed and department budgets. This is important for each individual department but also overall integration within the business, ensuring every area of a strategy is covered and no two departments are working on the same project. Simplicity and clarity are key as the plan must be easily understood and distributed across the organisation.
2.12.5 Assumption-based Planning (ABP)
All plans make assumptions about the future and identifying these assumptions are crucial to any plan. In the scenario of any assumption not occurring the organisation must have plans for how to react to this. Once these assumptions have been identified it is then important to identify which will have the biggest impact on the business if they were to fail. ‘Signposts’ can then be set up to monitor any potential issues and actions can be taken to manage the assumptions made. Finally, hedging actions can be taken to prepare for the instance where assumptions fail. As the business environment becomes more unpredictable and volatile ABP has become more crucial to strategies.
2.12.6Contingency Planning
This type of planning involves preparing for the worst case scenario to occur. All strategies have the potential to fail when they are affected by internal or external factors. This may be a supplier suddenly closing down, damage or loss of property or a change in government legislation. These events are often unavoidable, and hence instead of attempting to block them, plans need to be made for the event of them occurring. Firstly, a risk assessment should take place, highlighting the greatest potential risk to the business. Once risks have been highlighted plans can be made for if they occur, laying out the actions required, the triggers to the events, timeframes for action and budgeting. Contingency plans are often unused by the completion of the strategy, and hence ignored by many companies, but to initiate a strategy without one poses a serious risk to any business. Although they are rarely called upon, when they are they often save companies vast amounts of money.
2.13 Network diagram
Network diagrams serve as visual representations of a project. Network diagrams are complemented by
PERT and Gantt charts. In terms of planning and tracking a project from beginning to end, network diagrams are invaluable in today’s world. Both the project’s critical path and scope are defined. An effective project schedule network diagram will serve as a clear and concise representation of the project.
The Arrow diagram and the Precedence diagram are the two types of network diagrams that exist. In an Arrow diagram, nodes are used to depict events and arrows are used for activities, whereas activities are depicted in the order they occur in a Precedence diagram.
Network diagrams that use the arrow and node method allow you to depict clearly project dependencies. Through the use of a Gantt chart or an online project management software Sinnaps’ updated ‘Gantt-flow’, activity dependencies are clearly defined. Project managers and teams have a clear understanding of which activities or tasks must be completed in order to begin others and to therefor assign criticality to certain, more important tasks.
An activity network project diagram is a diagram visual representation of all the sequential and dependent activities within a project. The relationships between all the activities are represented by arrow and nodes. It is a toll used widely in project management due to its effectiveness in helping a project team in reaching its goal efficiently, working out project duration times and defining a project’s critical path.
Critical Path
When creating a critical path of a project, that is, finding out which activities are most critical to the project’s process, you must take into consideration which nodes will take the most and least amount of time. The critical path goes through all the nodes with the longest expected completion times.
In Sinnaps, the critical path is made clearly visible to users as it is highlighted at the top of the network diagram. Any activities that are running in parallel with the critical path must consider how long their completion will take and be on par with the critical path.
Most Likely Time
Most Likely time defines the expected completion time of the project. Usually, it is defined and based on the critical path.
Optimistic Time
If a project team wished to know the fastest time in which they could potentially complete the project, they must decide on the shortest possible time for each of the nodes. In this way, if they complete each node in its established shortest time, the project will be completed faster. This would be seen as the most optimistic outcome of the project.
Pessimistic Time
A project team may also wish to see what the worst-case scenario would be in terms of project duration. This is a useful feature of a network project diagram as it prepares both the project team and stakeholders for the worst. The team would have to decide on the longest possible amount of time that each node could take. After adding these values, the longest duration a project could take is produced and is seen as the most pessimistic outcome.
A bar (gantt) chart is ‘‘a graphic representation of project activities, shown in a time-scaled bar line with no links shown between activities’’ (Popescu and Charoenngam 1995, p. 96). The bar chart was originally developed by Henry L. Gantt in 1917 and is alternatively called a Gantt chart.1 It quickly became popular—especially in the construction industry—because of its ability to graphically represent a project’s activities on a time scale. Before a Bar (Gantt) chart can be constructed for a project, the project must be broken into smaller, usually homogeneous components, each of which is called an activity, or a task. No absolutely correct or incorrect way to break down a project exists; however, the scheduler should take a balanced approach and break it down into a reasonable number of activities that are easily measured and controlled without being overly detailed
On a Bar (Gantt) chart, the bar may not indicate continuous work from the start of the activity until its end. For example, the activity Getting a Building Permit may be represented by a 2-month-long bar. However, most of this time is a waiting period. Likewise, a Concrete Foundation summary activity may include several days of waiting for concrete to cure. Noncontinuous (dashed) bars are sometimes used to distinguish between real work (solid line) and inactive periods (gaps between solid lines) (Callahan, Quackenbush, and Rowings 1992)
Bar (Gantt) charts have become a vehicle for representing many pieces of a project’s information. Many variations of bar charts have evolved; some simply show the start and end of each activity Figures.
Alternative Bar (Gantt) chart for placing a simple slab on a grade placed in two parts
What are the main advantages of bar (gantt) charts
Bar (Gantt) charts have gained wide acceptance and popularity mainly because of their simplicity and ease of preparation and understanding. No ‘‘theory’’ or complicated calculations are involved. Anyone can understand them. They can be prepared anywhere with just a pencil and paper. So, although bar charts can carry—or be loaded with—other information, the user must be careful not to overload them and, thus, eliminate their main advantage: simplicity.
What are the main disadvantages of bar (gantt) charts:
The main disadvantage of Bar (Gantt) charts is lack of logical representation (relationships): Why did this activity start on that date? Bar (Gantt) charts do not reveal the answer. It could be a logical relationship, a resource constraint, or a subjective decision by the project manager. Although some software programmers tried to depict logical relationships on bar charts, the result was not always clear. The logic lines would get tangled, and unlike networks, bar charts do not allow the length of the bars to be subjectively changed or the bars to be moved around to make the chart look or read better.
Precedence Diagramming Method (PDM) is the most common method to draw network diagrams. So naturally, there will be some relationships and dependencies between the activities in Precedence Diagramming Method.
In order to complete the network diagram of a project with the method 4 types of relationships between the activities are used. These relationships are:
Early Start Dates
Starting dates can be assigned to each activity by doing a forward pass proceeding
From left to right in the network diagram beginning with the project start date. The
Dates derived by this method are the early start (ES) dates. The early start date for an
Activity is the earliest date the activity can begin. The estimate considers durations and resource availability calendars. To calculate early start dates, begin with the project start date and assign that date as the start date of activities that have no predecessor activities. Follow these steps to calculate the early start dates of subsequent activities, assuming finish-start relationships:
• Add the predecessor activity’s duration to its start date.
• Add the lag time or subtract the lead time.
• Refer to the resource calendar (or calendars) that applies to the people and
Equipment necessary for the activity, and add the number of off-days that the
Activity would span on those calendars.
• Assign the calculated date as the early start date of the successor activity
Doing this process manually is error prone and time consuming. Fortunately, there are
Computer programs to assist in the process, but the project manager must
understand the process well enough to recognize computer errors. Computer
software must be combined with common sense or good judgment.
Late Start Dates
The next step is to work through the network diagram from right to left beginning with
the mandated completion date, which is a milestone that is set in the project plan.
Subtract the duration of each activity in each path to determine the latest date the
activity could begin and still meet the project completion date. Resource calendars
must be considered in the backward pass as well as the forward pass
To calculate late start dates, begin with the project completion milestone and assign
that date as the finish date of its predecessor activities.
Activity-on-node is a project management term that refers to a precedence diagramming method which uses boxes to denote schedule activities. These various boxes or “nodes” are connected from beginning to end with arrows to depict a logical progression of the dependencies between the schedule activities. Each node is coded with a letter or number that correlates to an activity on the project schedule .Typically, an activity-on-node diagram will be designed to show which activities must be completed in order for other activities to commence. This is referred to as “finish-to-start” precedence – meaning one activity must be finished before the next one can start. In the diagram below, activities A and D must be done so that activity E can begin. It is also possible to create other variations of this type of diagram. For example, a “start-to-start” diagram is one in which a predecessor activity must simply be started rather than fully completed in order for the successor activity to be initiated.
An activity-on-node diagram can be used to provide a visual representation of the network logic of an entire project schedule. Or, it can be used for any smaller section of the schedule that lends itself to being represented as having a defined beginning and end. To keep the logic in the diagram simple, it may be most effective to include only critical path schedule activities. The planned start date of each node may also be listed in the diagram legend in accordance with the project management timeline.
Float, sometimes called slack, is the amount of time an activity, network path, or
Project can be delayed from the early start without changing the completion date of
The project.
Total Float
Total float is the difference between the finish date of the last activity on the critical
Path and the project completion date. Any delay in an activity on the critical path
Would reduce the amount of total float available on the project. A project can also
Have negative float, which means the calculated completion date of the last activity is
Later than the targeted completion date established at the beginning of the project.
Free Float
If activities that are not on the critical path have a difference between their early start
Date and their late start date, those activities can be delayed without affecting the
Project completion date. The float on those activities is called free float.
TOTAL FLOAT =LF-EF
TOTAL FLOAT=LS-ES
Both of these formulas produce the same result
2. Free Float: The amount that a task can move without affecting other tasks.
FREE FLOAT =ES2-ES1
The reason there are two types of float is because a delayed task is probably not a concern if the next task is able to “absorb” the delay. Future tasks are delayed in a domino effect, but unless the delay reaches the total float, the overall project completion date is unaffected.
That being said, traditional network diagramming techniques use the total float, so project management is normally based on the total float, while free float is not used unless it is necessary.
How to Calculate Total Float
Total float is calculated using a network diagram. Although there are a few steps, network diagrams are not very difficult to produce and a simple step by step process is not hard to remember.
Step 1: Divide the Project into Tasks
The project is subdivided into its constituent tasks. This is usually called a Work Breakdown Structure (WBS), although the Project Management Body of Knowledge (PMBOK) differentiates between a WBS and an Activity List. The WBS is actually a deliverable-oriented subdivision of the work, focusing on the project deliverables rather than strictly tasks to be completed.
Make sure each task represents one interrelated unit of work. If you have too many tasks, it becomes burdensome and micromanaged. If you have too few tasks, there is little point in creating a network diagram because large, unrelated work is managed within the same task.
Step 2: Determine the Network
Once the tasks are chosen, the network is created by way of task dependencies, that is, each task’s predecessor tasks are determined. For example,
Step 3: Enter Task Durations
The task durations are an integral step in the schedule and they must be estimated accurately. Once the task durations are known, they are entered into the top, middle box.
Once the task durations are entered, it’s time to proceed to the forward pass. I’ll walk you through this step by step.
Step 4: Perform Forward Pass
The purpose of the forward pass is to determine the Early Start (top left box) dates, usually abbreviated ES, and the Early Finish (top right box) dates, usually abbreviated EF, for each task. These are defined as the earliest dates that the task can start.
The grand result of the forward pass is the completion date of the project, which is the EF (top right box) of the final task.
The step by step instructions are:
EF=ES+DURATION-1
The reason you have to subtract one is because the task start and end days are inclusive of the duration. For example, if you will be working on a task from days 1 – 5, that is a duration of 5 days, because days 1 and 5 are both included in the task duration.
3. Calculate the ES of the next task.
ES2=EF1+1
Step 5: Perform Backward Pass
The purpose of the backward pass is to determine the Late Start, LS, (bottom left box) dates and Late Finish, LF, (bottom right box) dates for each task. These are defined as the earliest date that the task can finish, and the latest date that the task can finish, without affecting the completion date of the project.
To perform the backward pass, do the following step by step procedure.
LS=LF-1
3. Calculate the LF of the previous task.
LF2=LS1-1
Step 6: Determine Task Floats
Finally, we’re getting there. The Total Float is simply the bottom boxes minus the top boxes. It doesn’t matter whether the left or right side is used, the result will be the same.
A few conclusions from the example:
The Program Evaluation Review Technique, commonly known as PERT, is a visual tool in project planning that helps organizations analyze and represent the activity, and evaluate and estimate the time required to complete the project within deadlines. PERT allows planners to identify start and end dates, and ultimately reduce costs and time needed to complete the project.
Step 1. Identifying specific activities and milestones
By listing all your tasks in the table, you get a clear overview of all the steps which you can subsequently expand by adding information on sequence and the time necessary to complete each activity.
Step 2. Determining the sequence of activities
While it easy to predict the order of some activities, other tasks may require more in-depth analysis which will help you determine their order more easily
Step 3. Constructing a network diagram
Once you established the sequence of activities, you can represent both serial and parallel activities in the diagram. Each activity should represent a node in the network, and you can use arrows to show relationships between activities.
Step 4. Estimating the time necessary for each activity
What distinguishes PERT from other techniques is its ability to deal with uncertainty in activity completion time. There are three-time estimates this model typically uses for each activity:
After you identified the time estimates, you can calculate the expected time for each activity by using the following weighted average:
Expected time = ( Optimistic + 4 x Most likely + Pessimistic) / 6
For example, imagine you are building a cottage. Drilling and planting the posts has an optimistic duration of 7 hours, an expected duration of 10 hours, and a pessimistic duration of 12 hours. The optimistic duration is counted once, the most likely time is counted four times and the pessimistic time is counted once.
The entire sum is then divided by 6 and the weighted average is 9,83.
Step 5. Identifying the critical path
By adding the times for the activities and determining the longest path, you create a critical path. The critical path involves the total amount of time necessary to complete the project. The total project time doesn’t change if activities outside the critical path speed up or slow down.
A project can be sub-divided into a set of predicable, independent activities.The precedence relationships of project activities can be completely represented by a non-cyclical network graph in which each activity connects directly into its immediate successors.Activity times may be estimated either as single point estimates or as three point estimates (i.e. optimistic, pessimistic or most likely) and are independent of each other.Activity duration is assured to follow the beta distribution, the standard deviation of the distribution is assumed to be 1/6th of its range.Mean (te) is assumed to be = .Variances in the length of a project is assumed to be = sum of variances of activities on the critical path.The duration of an activity is linearly related to the cost of resources applied to the activity.
the three-point estimate is a simple yet useful approach to estimating the time or cost of work items. According to the PMI methodology, it is used in the process groups “Estimate Activity Duration” and “Estimate Costs”. The technique involves three different estimates that are usually obtained from subject matter experts:
The optimistic estimate is the expected amount of work or time needed to perform an activity assuming no impediments occur and everything is going smooth. It represents the so-called best-case scenario. The pessimistic point is based on the assumption that the opposite was true – it represents the worst-case scenario. Although both estimates are referring to the extreme points of the range of expected outcomes, the estimates are supposed to be somewhat realistic.
The third point reflects the most likely case, it is the estimation of work or time that is deemed to be the most realistic. One could be tempted to simply use the mean between the optimistic and pessimistic points without giving it a second thought. However, this may not be appropriate for many cases. In practice, it is normally worthwhile to determine this most likely estimate properly, analogous the other estimation points.
The result of three-point estimating is a so-called triangular distribution of time values or cost amounts, comprising of the three estimates (see illustration below).
When we code in any programming language we need to store data in different type of objects, sometimes list of objects, object of objects etc. How do we store the data and we must know how to design a data structure which should be efficient to manipulate it like time of insertion, deletion, search.
In this article we will learn, what is queue and stack, how to implement them with some access methods and then we will analyze their efficiency.
Stack: follows FILO (First In Last Out). Where one who comes first is served last. Insert and delete operations are held at same end.
Queue: follows FIFO (First In First Out), similar to any queue (i.e. at ticket counter). Where one who come first is served first.
In above figure we can see stack is having only one pointer to perform operations but queue has two pointers where tail is used to insert and head is used to remove.
Analysis
Stack: In stack as seen in both methods Push and Pop we don't have any loops, to push or pop we need only O(1) time, no need to traverse the whole array because operation is happening on top of single end. So only O(1) time is required to push and pop, if we want to traverse or pop all the elements it will take O(n) time, where n is the number of elements in stack.
Queue: Same as stack, we need only O(1) to EnQueue and DeQueue the element because both operations are happening at individual ends. And traversing or removing all elements from queue will take O(n) time where n is the number of elements in queue
Project Evaluation and Review Technique (PERT) is a tool that project management uses to manage a project. The PERT chart contains information about subprojects and estimated completion times. Each subproject is assigned an estimated completion time, based upon probability distributions for the expected completion time for the subproject from start to finish. The probability distribution for expected time is calculated by the following equation: Expected time = (Optimistic Time + 4 x Most likely Time + Pessimistic Time) / 6.
Add the Optimistic Time for a subproject to the Pessimistic time for the same subproject. For example, if your subproject’s optimistic time is one day, and Pessimistic Time is seven days, the total for this step is eight days.
Multiply the Most Likely Time by four. If the most likely time is two days, then two days times four is eight days.
Add your answer from Step one to your answer from Step two. For the example, eight days + eight days is 16 days.
Divide your answer in Step 3 by 6. For the example, 16 days / 6 is 2.67 days (rounded). 2.67 days is the expected time for this subproject.
Repeat Steps 1 through 4 for each subproject in your PERT Chart. When you finish, you'll have calculated expected values for each step of your entire project schedule.
Key -takeaways
Building structures are generally constructed on concrete foundations. Based on the soil type and water table level of the area, the foundation chosen can vary. If necessary, soil testing is performed to check the bearing capacity
Reference
1. Punmia, B.C khandewala k.k. project planning with PERT and CPM, laxmi publication, 2016.
2. National building code, bureau of Indian standards, new Delhi, 2017.
