Project Time Management Tutorial

Welcome to the sixth lesson Project Schedule Management of the PMP tutorial, which is part of the PMP Certification Course offered by Simplilearn. In this lesson, we will focus on project schedule management. Let us begin with the objectives of this lesson.

Objectives

After completing this lesson, you will be able to:

  • Define Project schedule Management

  • Explain project schedule, Gantt charts, and network diagrams

  • Identify the key terms used in Project schedule Management

  • Describe the Project schedule Management processes

  • Explain various schedule network analysis techniques.

Let us begin with the first topic of this lesson, project schedule management.

Project schedule Management

The purpose of project schedule management is to ensure that the projects get completed on schedule. This knowledge area is primarily concerned with developing a project schedule and ensuring that project goes as per the agreed schedule. If there is a need to change the project schedule, the change should happen by following a proper change control procedure.

Another term used in the PMP examination is schedule management plan. Schedule management plan is part of the project management plan and has information on the planned project schedule and its management and control.

Let us discuss the key activities of project schedule management in the next section.

Project schedule Management Activities

The key activities that are part of the project schedule management include:

  • Identifying activities

  • Estimating schedule and resources

  • Sequencing activities

It is important to identify a list of activities that would be a part of the project.

Next, an estimation of schedule and resources required for completing the identified activities are done. Finally, these activities need to be sequenced as per the dependencies.

In the next section, let us discuss project schedule.

Project Schedule

Project schedule represents the schedule dimension of the project plan and has information like when the project would start, when each of the project activities would happen, in what order the project activities would happen, when the project would be completed, etc. Usually, a software system is used to develop the project schedule.

The project team can enter the list of activities in the software as well as their dependencies, and the software can produce the project schedule as the output. Microsoft Project is the most popular tool used for project schedule development. Generally, the project schedule is considered similar to project management plan.

Project management plan is different from project schedule. Project management plan not only has information about the project schedule, but also other important project related plans, like risk management plan, cost management plan, etc.

Let us focus on Gantt chart in the next section.

Gantt Chart

Gantt chart is a type of bar chart that illustrates a project schedule. It shows the dependencies between the project activities as well as their percent completion. A sample Gantt chart is shown in the section.

Chart - Gantt Chart

Two summary elements of the work breakdown structure are depicted. To complete those elements, there are some activities under them. Some of these activities have dependencies.

For example, Activity B and C have a dependency. Activity C can start only when Activity B is completed.

The chart gives you an idea of when specific activities are planned to finish and when the overall WBS (pronounce as W-B-S) element will get delivered. Create tasks and work with the Gantt chart. This will make answering Gantt chart based questions easy and fun.

In the next section, let us understand the relationships that exist among project activities.

Gantt Chart-Relationships

Project activities are related to each other, and this relationship can be broadly classified into four types:

Finish to Start: An activity must finish before the successor can start.

For example, Activity B can start only when Activity A completes.

Start to Start: An activity must start before the successor can start.

For example, Activity B can start only when Activity A starts.

Finish to Finish: An activity must finish before the successor can finish.

For example, Activity A has to complete before Activity B can complete.

Start to Finish: An activity must start before the successor can finish.

For example, Activity A has to start before Activity B finishes.

The relationships among project activities can be classified as follows:

Diagram - Gantt Chart: Relationships

Out of these four types, the Finish to Start is the most commonly used and Start to Finish is the least used real-life projects. Along with these relationships, you also need to be aware of the “dependencies.”

Let us look at the dependencies in the next section.

Gantt Chart-Dependencies

There is a subtle difference between dependency and a relationship. Dependency is how activities are interdependent in one way or the other. There are two ways of classifying dependencies. The first classification is mandatory or discretionary. The other way of classifying dependencies is external or internal.

Classification 1

  1. Mandatory dependencies cannot be passed by. For example, the foundation of a civil structure must be laid before working on the pillars and slabs.

  2. Discretionary dependencies, on the other hand, arise out of the preferences of the project team. For example, painting activities can be started only after all the electrical and plumbing work is done.

Classification 2

  1. External dependencies involve a third party or an entity outside the project team. For example, if a construction project is dependent on the approval of the structural design by a government authority, it becomes an external dependency.

  2. Internal dependencies are within the control of a project team. For example, the start of the slab work being dependent upon the availability of ready-mix concrete may be an internal dependency.

In the next section, let us look into network diagram.

Network Diagram

A network diagram is extensively used in the project schedule management knowledge area to plot the activity dependencies. This is a graphical representation of the project activities in the form of a network.

Network diagrams can be drawn in one of the following two ways:

Precedence Diagramming Model (PDM) or Activity on Node (AON)

In precedence diagramming model:

Boxes represent activities:

  • Arrows indicate dependencies

  • Relationships can be of four types:

    • Finish to Start

    • Start to Start

    • Finish to Finish

    • Start to Finish

Arrow Diagramming Model (ADM) or Activity on Arrow (AOA)

In arrow diagramming model:

  • Arrows are used to represent activities

  • The direction of the arrows indicates the relationships and sequences

  • Only Finish to Start relationships can be shown

  • Dummy activities may be required to show a dependency

There may be questions in the PMP exam, based on the Network Diagram. To create and work with the diagram. This will make answering Network diagram based questions easy and fun.

In the next section, let us look at a sample network diagram.

Network Diagram - Example

A sample network diagram is shown in the section.

Diagram - Network Diagram - example

Activities A and C can happen in parallel. B and D require both A and C to complete, whereas E requires both B and D to complete.

Activity on Arrow network diagram makes use of “Hammock Activities.” They are used to show a comprehensive summary activity combining several other activities underneath for control and reporting purposes.

Let us now look at a business scenario to understand this process better. In the next section, let us look at few important terms in schedule management.

Key Terms

Given below are the key terms used in Project Schedule Management:

Leads and Lags

When a successor activity can start before the predecessor activity can complete, it is considered Lead. For example, you can start preparing the test environment two weeks before the development activity finishes.

When the successor activity has to wait for few days after the predecessor activity has been completed, it is considered Lag. For example, one needs to wait for two days for the foundation to settle, before work on the pillars for the next floor starts.

Rolling Wave Planning

Rolling wave planning is an iterative planning technique in which the work to be accomplished in the near term is planned in detail, while the work in the future is planned at a higher level. It is a form of progressive elaboration.

Analogous Estimating

In the context of estimating techniques, analogous estimating is based on the previous project data. Therefore, if the last five similar projects took six months to complete, the next one will also take six months. This technique employs expert judgment.

In the next section, let us look at a few more key terms used in project schedule management.

Parametric Estimating

Another estimating technique is parametric estimating. This technique uses a mathematical model to calculate the projected schedule for an activity based on the historical records from previous projects and other information.

Few common parameters are identified based on the previous project data, and that parameter is used to predict the schedule required to complete the next activity or project. For example, you can normally complete 10 kilometers of highway construction lanes, a week.

Effort

The effort is the total amount of work required to complete the activity.

Duration

Duration is the amount of schedule it takes regarding elapsed or calendar days. If you have an activity that requires ten people to work for five days, the total effort is 50 person days, but the duration is only five days.

Decomposition

Decomposition is the technique of breaking a task into smaller pieces. Note: Decomposition should continue until there is no further value from decomposing the task further or until it can be estimated accurately.

In the next section, let us look at the project schedule management processes.

Project schedule Management Processes

There are six project schedule management processes; they are plan schedule management, define activities, sequence activities, estimate activity durations, develop schedule, and control schedule.

The first five processes are executed during the planning process group. The ultimate goal of these planning processes is to develop the project schedule. The sixth and the last process is a part of the monitoring and controlling process group.

In the next few sections, let us discuss these processes in detail. We will begin with plan schedule management.

Plan Schedule Management

As defined in PMBOK Guide, plan schedule management is the process of establishing the policies, procedures, and documentation for planning, developing, managing, executing, and controlling the project schedule. It belongs to the planning process group.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram - Plan Schedule Management: Inputs, Tools & Techniques, and Outputs

Inputs

The project management plan

The project management plan provides other subsidiary plans and will guide the schedule planning activities on the project.

The project charter

The project charter provides an overall context and the high-level product and project description, which might help determine the approach to schedule management. Few projects might have scheduling constraint.

For example, projects of Olympics 2016 should be completed at the same schedule.

Enterprise environmental factors

Enterprise environmental factors provide the organizational context to the project, including the culture of the organization, the infrastructure like scheduling systems available, key personnel, and so on.

Organizational process assets

Organizational process assets provide inputs such as policies and procedures, templates, past performance data and estimates, historical information, and knowledge base.

Now, let us look at the tools and techniques employed in this process.

Tools and Techniques

Expert judgment

Expert judgment refers to input received from knowledgeable and experienced resources. Experts can draw from their previous experiences the proper approach to govern the schedule on a project.

Meetings

Meetings may be organized to determine the schedule management plan. Anybody responsible for the project schedule management, such as the project manager, sponsor, customer, and other stakeholders must attend these meetings.

Data Analysis

Several analytical techniques may be used to determine the schedule management plan. These may include different planning approaches and philosophies such as “rolling wave planning” or different scheduling software that allow to build “what-if” scenarios, and study the effect of advanced scheduling techniques like leveling, fast-tracking, and crashing.

Now, let us look at the outputs of this process.

Output

Schedule management plan is a component of the project management plan that describes the criteria and activities required to arrive at the project’s schedule, as well as how the project may be baselined, monitored, and controlled.

In the next section, let us the define activities process.

Define Activities

Define activities is the process of identifying the specific actions to be performed to produce the project deliverables. It belongs to the planning process group.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram - Define Activities: Inputs, Tools & Techniques, and Outputs

The important input for the define activities process is the scope baseline. Scope baseline is a term used collectively to refer to project deliverables, constraints, and assumptions of the project.

In addition to the scope baseline, the other inputs in this process are enterprise environmental factors, organizational process assets, and schedule management plan. A reason why enterprise environmental factors is an input to define activities is that the organization might be using project management software to define activities and that may influence the activity definition process.

The knowledge base containing historical information, regarding activities lists, used by previous similar projects is a good example of organizational process assets applied to schedule. The tools and techniques used in defining activities are decompositions and rolling wave planning.

The last technique is expert judgment, where the experience of project team members is used in developing detailed activity list. The output of the process is activity list, activity attributes, and milestone list. Activity list contains a list of identified activities.

Activity attributes are the additional information about the activity itself. A milestone is a significant point or event in the project. A milestone list identifies all the milestones and indicates whether the milestone is mandatory or optional.

Let us move on to the next process, sequence activities.

Sequence Activities

Sequence activities are the process of identifying and documenting relationship among the project activities and is also part of the planning process group Every activity and milestone, except the first and last one, is connected to at least one predecessor and one successor.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram - Sequence Activities: Inputs, Tools & Techniques, and Outputs

The inputs to this process are activity list, activity attributes, and milestone list. All these are the outputs of the define activity process. The other inputs are schedule management plan and project scope statement. Schedule management plan provides guidance regarding methodology to be employed for many of the scheduling activities on the project.

Organization process assets are also inputted into sequencing activities because the organization might have some kind of knowledge base for scheduling project activities. The enterprise environmental factors relevant to this process may be scheduling tools in use, project management information systems, work authorization systems, etc.

One of the important tools and techniques used in sequencing activities is the precedence diagramming method. In this method, the activities are drawn on a network diagram, and all the different kinds of dependencies between the activities are determined. While determining activity dependency, it is important to identify the type of relationship or dependency between the activities.

The other technique is Leads and Lag, which is widely used for sequencing activities. The output of the process is the project schedule network diagram, which is a graphical representation of the project activities in the form of network, which also shows the activity dependencies.

While designing the network diagram, new activities might be identified, and that would result in some of the project document updates, especially the ones that list all the project activities.

In the next section, let us look at the estimate activity resources process.

Estimate Activity Resources

After sequencing the activities, the next step in project schedule management is estimating the resources required to accomplish each of the identified activities. Estimate activity resources process also belongs to the planning process group. Here, resources do not mean only the human resources but include all other resources like equipment, raw materials, machinery, etc.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram -

Schedule management plan is the first input. Schedule management plan provides guidance regarding methodology to be employed for many of the scheduling activities on the project. The other inputs to this process are an activity list, and activity attributes that are the outputs of the schedule management processes.

The risk register is another input. Risks to the project may influence the decisions about the resources that need to be deployed; hence risk register becomes an input to this process. Also, activity cost estimates are another input. Cost and resource estimates on a project are interrelated and influence each other.

For example, the cost might dictate the number and type of resources that can be employed or the schedule might dictate the cost that may need to be incurred. Along with this, the resource calendar is also an important input, because it has the information about the availability of each of the resources.

Some of the enterprise environmental factors that can influence estimating activity resources are the availability of required resources within the organization. The organizational process assets is also an important input as the organization might have standard policies for staffing or for hiring contractors on the project.

With all these inputs available for estimating activity resources, there are various techniques used for estimating the required resources. The first technique is using expert judgment. In this technique, an expert in resource planning and estimating can estimate each of the activities.

The next technique used is alternative analysis. In this, the activities are analyzed to identify different ways of completing them. This is to ensure only the required resources are assigned to each of the activities. This helps in resource optimization.

Along with the above two techniques, many organizations routinely publish their estimating data, and this could be used in activity resource estimation. Another technique that is routinely used in activity estimation is bottom-up estimating, which is decomposing the activity further down to understand it in more detail and estimating at that level.

Later, all such estimates are added to arrive at the estimate of the activity. In real projects, one has to use all of the above to estimate each of the activities. Some schedules the project management software also helps in estimating. The software estimates are based on the inputs provided to it.

Software should only be considered as a supporting tool in estimation and never fully rely on its output. The output of this process is the activity resource requirements. Along with this, resource breakdown structure is also prepared.

The resource breakdown structure is the categorization of all the required resources in various categories, i.e., human resources, equipment, raw materials, etc. In the process of estimation, several other project documents may also be updated. For example, the resource estimates are directly correlated with cost estimates.

Let us now move on to the on to the next process, estimate activity durations.

Estimate Activity Durations

The next process is to estimate the duration required to complete each of the activities. The duration estimation should be done by someone who is familiar with the project. For example, the same activity, if done by a highly skilled resource would take less schedule compared to a less skilled resource.

This may vary regardless of the resource used due to the project requirements. Also, the activity duration estimation should be updated continuously as you move ahead with the project because as the project progresses, there will be more clarity on the project.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram - Estimate Activity Durations: Inputs, Tools & Techniques, and Outputs

The inputs of this process are similar to the ones in sequence activities process. Schedule management plan is the first input. Schedule management plan provides guidance regarding methodology to be employed for many of the scheduling activities on the project.

For instance, it may contain information about the estimation techniques to be employed and the people who need to be involved in the estimation process.

Activity resource requirements is also an input to this process because resources assigned to an activity would significantly affect the activity duration, i.e., the lower skilled resources would take more schedule than the highly skilled resources. The other inputs include activity list, activity attributes, and resource breakdown structure. Resource calendars are also inputted into this process.

The type and skill set of resources available to the team may have an impact on the schedule it would take to complete the activities. Risks to the project may influence the decisions about the schedule required to complete the activity. Hence risk register becomes an input to this process. The project scope statement defines the constraints and assumptions affecting the project duration.

An example of enterprise environmental factor that can affect duration is organization’s productivity metrics, which is collected based on the experiences of multiple projects. The last input in this process is organizational process assets.

Now, let us look at the tools and techniques used for estimating activity durations.

First is the expert judgment, which means using previous project experiences in estimating the current project duration. This can be used with other estimation techniques; and used to reconcile differences if different techniques result in different estimates.

Three-point estimating is a method where three estimates are used instead of one. It is part of a project management philosophy known as Program Evaluation and Review Technique (PERT) (pronounce as Pert).

Estimating activity durations is often done as a team exercise as each activity may require multiple skill sets to be applied. Therefore, it is important to use group decision-making techniques to arrive at a consensus or at least an estimate that is acceptable to all the team members.

Reserve analysis adds buffer into the project schedule to deal with any uncertainty. The contingency reserve may be added as a percentage of the activity duration or fixed number of work periods. The other tools and techniques are analogous estimating and parametric estimating.

The outputs of this process are the activity duration estimates and project documents updates. The activity duration estimates are represented regarding the range of possible results. For example, ten days plus minus two days: i.e., the activity would take a minimum of 8 days and a maximum of 12 days.

In the next section, let us look into a business scenario to understand this concept better.

Business Scenario: Problem Statement

Jan, the EVP of the manufacturing division, has commissioned Jack to lead a project initiative in her area of responsibility because of his attention to detail. Jack is working with his team to estimate activity durations so they can map out the schedule for the project.

After a successful decomposition process of the scope statement of work, Jack is confident in his team’s ability to capture the true work effort that needs to be estimated and scheduled.

In reviewing the activities to be estimated, Jack realizes that a large number of the activities could benefit from some historical data and the use of mathematical parameters. This minimizes his estimating risk for 60% of the activities.

For the remaining activities, the team can research past practices and industry standards to come up with a range of estimates based on optimistic, pessimistic and realistic durations. What approach are Jack and his team likely to take to determine their estimates?

Let us look at the problem solved now.

Business Scenario: Solution

Jack and his team have decided to use parametric estimation technique for a large number

of activities and have decided to use three-point estimate for the remaining activities. This is

also known as PERT.

Let us now look into the next process, i.e., develop a schedule.

Develop Schedule

Develop schedule is the process of analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule. It belongs to the planning process group. Generally, scheduling software is used for developing the project schedule.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram - Develop Schedule: Inputs, Tools & Techniques, and Outputs

Entering the activities, durations, and resources into a scheduling tool generates a schedule with planned dates for completing project activities. Developing a project schedule is an iterative process. Revising and maintaining a realistic schedule is a task in itself, and it continues throughout the project as the work progresses.

The most of the inputs of this process are the outputs of estimate activity durations process. They are:

  • Risk register

  • Project scope statement

  • Project staff assignments

  • Resources calendars

  • Organizational process assets

  • Enterprise environmental factors

  • Schedule management plan

  • Activity list

  • Activity attributes

  • Project schedule network diagrams

  • Activity resource requirements

  • Resource breakdown structure

  • Activity duration estimates

Various tools and techniques are used to develop schedule process. Schedule network analysis is a technique that generates project schedule. It employs various analytical techniques such as critical path method, critical chain method, modeling techniques, and resource optimization techniques to create the project schedule.

The other tools and techniques include leads and lags, schedule compression, and scheduling tool.

Let us now look at the outputs of this process.

The project schedule consisted of a minimum planned start date and planned finish date for each activity. Although project schedule can be represented in tabular format, it is more often represented graphically using either bar charts or network diagrams or a combination of two. The final schedule which is the output of the developing schedule process is also called “schedule baseline.”

Once the scheduled is baselined, it can be changed only through formal approvals. Meeting the schedule baseline is one of the measures of project success. Schedule data produced may include some resources, key milestones, etc.

Project calendars specify the available working days and the number of shifts in each day. It indicates how many hours and days are available for the work of the project to be completed.

Project management plan updates are a result of the developing schedule process, many of the other subsidiary plans of the project plan may get impacted, which may include cost management plan, scope management plan, risk management plan, etc. This may also result in other project documents being updated.

In the next few sections, let us discuss schedule network analysis techniques.

Schedule Network Analysis

It is essential to know if the required resources are available at that schedule, along with the schedule estimate of each of the activities. Since scheduling is calendar based, it helps in estimating the same. Schedule network analysis technique generates project schedule.

There are various schedule network techniques and are explained as follows.

Critical Path Method

Critical path method relies on determining the critical path on a project schedule.

Critical Chain Method

Critical chain method is a variant of the critical path method wherein the critical chain is determined based on the logical, resource, and other kinds of dependencies between the activities.

What-If Scenario Analysis

What-if scenario analysis is about trying to vary a certain parameter to observe the impact on the schedule. For instance, you may want to check result, if you put in more resources on a particular activity to reduce its duration.

Resource Optimization Techniques

Resource optimization techniques try to arrive at the optimal utilization of the resources used on a project. Ideally, you would want the resources to be fully utilized, but you would also want to build in sufficient buffers in case a certain resource is not available due to various reasons.

In the next section, let us look at the Program Evaluation and Review Technique.

Program Evaluation and Review Technique

Program Evaluation and Review Technique is based on three-point estimates for an activity. The pessimistic estimate refers to the worst-case scenario, whereas most likely estimate is what you expect to happen in a realistic scenario.

The optimistic estimate, on the other hand, represents the amount of schedule an activity would take in the best-case scenario. Based on these three estimates, the expected duration of the estimate is calculated as (μ) = (P+4M+O)/6

The formula for calculating the standard deviation of activity and variance of activity is:

(σ) = (P-O)/6

There is no question asked on variance, but the formula is important, because, if the standard deviation of the whole project is to be calculated, the process is to calculate the variance of the whole project and then take its square root to calculate the standard deviation of the project.

To calculate the variance of the activity:

σ ^ 2

Concept-based questions on PERT can be expected in the PMP exam. So make a note of the formulae while you prepare for the exam.

In the next section, let us understand PERT with an example.

PERT-Example

Let us now figure out how we can apply the three-point estimation that PERT uses to draw some useful conclusions.

Assume that the optimistic, pessimistic, and most likely estimates are 20, 70, and 30, respectively. Using these values, you can determine the expected duration and the standard deviation as indicated.

Now, if the causes of variation are random, you can assume that the actual values would be evenly distributed about the mean, and will follow the normal distribution—some schedules referred to as the Bell curve.

Image -Bell curve

Further, you can use the properties of the normal distribution. There is 68% probability of the actual value falling within the first sigma from the mean, 95.4% probability for the second sigma, and 99.7% probability of the actual value falling within the third sigma.

Extending this logic, the notion of Six Sigma is reaching a level of confidence that only 3.4 schedules out of a million would the actual value fall outside the stated range. PERT allows you to plan based on the intended “level of confidence” in the outcome and determine buffers accordingly. Let us discuss the critical path method in the next section.

Critical Path Method

The critical path is defined as the longest duration path through a network diagram, which determines the shortest schedule to complete the project. The float can be considered as a buffer schedule available to complete an activity.

The float is calculated once the network diagram is ready. It is also called as slack. There are three kinds of the float as follows:

Total Float (Slack)

The first being the total float, which is the amount of schedule activity can be delayed without delaying the project end date or an intermediary milestone.

Free Float

The second type of float is a free float, which is the amount of schedule activity can be delayed without delaying the early start date of its successor(s) activities.

Independent Float

The last type is an independent float, which is the amount of schedule activity can be delayed if all the predecessors finish at their latest finish dates and you want to start all the immediate successors at their earliest start dates.

The slack of the activities on the critical path is zero because there is no scope to delay activities on the critical path. The critical path represents the project duration. Delaying activities on the critical path is as good as delaying the project duration. Concept-based questions on critical path can be expected in the exam. So it is essential to have a clear understanding of the concept.

In the next section, let us learn how to calculate float.

Calculation of Float

Two methods can calculate float of an activity. However, the first step in critical path method is to identify the critical path of the network. Once the critical path is identified, follow the forward pass to find the early start and early finish for each activity.

The float of the activities on the critical path is zero, so they represent the overall project duration. Use forward pass or backward pass to calculate the total activity schedule.

Calculate late finish and late start using backward pass method. Note the total float formula before you start for the exam.

Total Float = Late Start – Early Start or Late Finish – Early Finish

In the next section, let us look at forwarding pass and backward pass methods in detail.

In forward pass, you can either go through the network starting with schedule zero and keep calculating the schedule required to complete each of the activity until you reach the last activity of the project.

Diagram -Calculation of Float

The starting schedule for each of the activity in this approach is called “early start,” and the end schedule for each activity is called the “early finish.” Alternatively, in backward pass, you can travel through the network from the project end date and calculate the schedule required to complete each activity. The end date in this approach is called the late finish, and the start date of the activity in this approach is called the late start.

The float of the activity is either the difference between the late start and early start or the difference between the late finish and early finish. Both the differences work out to be the same. Before the start of the PMP exam, please make a note of the total float formula.

Let us understand the critical path calculation with an example in the next section.

Critical Path-Example

Given below is the calculation of a critical path:

Image-  the calculation of a critical path

There are five activities in this project and two paths in the network diagram. Start, 1, 2, 4, 5, End is one path and Start, 1, 3, 5, End is the second path. Since the duration of the path Start, 1, 2, 4, 5, End is 18 days, which is more than the duration of the path Start, 1, 3, 5, End, the critical path of the project is Start, 1, 2, 4, 5, End.

Let us take activity 3 as an example. First, calculate the early start and early finish dates. Activity 3 can start only after activity 1.

Since the early finish of activity 1 is 3, it becomes the early start of activity 3. Activity 3 cannot start earlier than 3, because activity 1 can be completed only by then. Therefore, early start of activity 3 is 3. Since the duration of the activity is four days. The early finish of activity 3 is 3 + 4 = 7 days.

Now, let us calculate the late start and late finish of activity 3. The late start of activity 5 is 14 days. The activity 3 happens just before activity 5, so the late finish of activity 3 is 14 days. To calculate the late start, you can subtract the duration from the late finish. Therefore, the late start of activity 3 is 14 - 4 = 10.

In the next section, let us focus on schedule compression.

Schedule Compression

Schedule compression is done to optimize the schedule or to meet some externally imposed deadline on the project.

For example, you followed critical path method and arrived at the project duration of, say 100 days, whereas the customer wants to get the project done in 95 days. In such cases, schedule compression techniques are used to see if the schedule can be compressed to reduce the schedule by five days.

There are two popular schedule compression techniques. They are fast-tracking and crashing.

Fast Tracking

In fast-tracking, activities that normally happen in the sequence are checked if they can happen in parallel. Typically, this would involve sacrificing some of the discretionary dependencies. If more activities can be done in parallel, it speeds up the project.

For example, if you look at the diagram, activities B and C were to be done in sequence.

Diagram - Fast Tracking

However, if you can find a way to do them in parallel, you may be able to save schedule.

Crashing

Crashing involves increasing the cost to save schedule.

For example, if you can use more resources or resources that are more skilled or advanced techniques to compress the schedule lines, you would end up making cost and schedule tradeoffs to determine how to obtain the greatest amount of schedule compression for the least incremental cost while maintaining the project scope.

Concept-based questions on schedule compression can be expected in the exam. To ensure that you have a good understanding of the topic.

In the next section, let us look at an example of schedule compression.

Schedule Compression-Example

Look at the four activities in the table.

Activity



 

Original

Duration (in

Days)

Crash

Duration (in

Days)

schedule

Savings

Original

Cost in

Dollars

Crash Cost

Extra Cost

Crash Cost

per Day

A

10

8

2

10,000

12,000

2,000

1,000

B

14

10

4

14,000

24,000

10,000

2,500

C

5

4

1

15,000

17,000

2,000

2,000

D

9

7

2

12,000

18,000

6,000

3,000

The normal cost of executing each of the activities as well as how much each of the activities can be crashed is also provided. Which activity would you crash to reduce the project schedule by one day?

Activity A will be crashed if the duration of the project is reduced by one day, as the ‘per unit cost’ of crashing the activity A is the least. All the activities are assumed to be on the critical path here. While crashing, if you end up saving schedule on a path, which is not the critical path, you will not end up saving schedule on the project.

In the next section, let us look into the impact of schedule compression.

Impact of Schedule Compression

Different schedule compression techniques have a different impact on the project.

Impact of schedule compression on projects are as follows:

Schedule Compression

Technique

General Impact to the Project

Fast track

  • Adds risks

  • Increases management schedule for the project manager

Crash

  • Adds costs

  • Increases management schedule for the project manager

Reduce scope

  • Saves schedule and cost

  • Increases customer dissatisfaction

Cut quality

  • Saves cost and resources

  • Increases risks

Resource reallocation

  • Does not add cost or increase risks

The impact of fast-track leads to risk additions and increase in management schedule for the project manager. Crash leads to cost addition and increase in management schedule for the project manager.

Reduce scope, on the other hand, saves cost and resources but increases customer dissatisfaction. Likewise, cut quality saves cost and resources but increases risk. Resource reallocation does not add cost or increase risk.

In the next section, let us look into the other techniques used in scheduling.

Other Scheduling Techniques

There are several techniques that are used in scheduling projects.

What-if scenario analysis: In this technique, questions like, “What if a particular Scenario changed on the project, would that produce a shorter schedule?” are put forth to understand the impact of specific changes on the schedule. The goal is to produce a realistic schedule.

Monte Carlo analysis: In this method, a computer simulates the outcome of a project, making use of randomly generated values that map the probability distribution of the input variables. Together, these two techniques are called modeling techniques.

Resource optimization techniques: These are also used to produce a resource-limited schedule. Resource optimization results in a more stable number of resources used in the project.

Critical chain method: This technique develops the project schedule that takes into account, both the activity and resource dependencies.

In the next section, let us look at the last process in project schedule management, control schedule.

Control Schedule

Control schedule is concerned with determining the status of the project schedule, determining that the project schedule has changed, and managing the actual changes as they occur.

Let us look at the inputs, tools, techniques, and outputs to this process in the following diagram.

Diagram - Control Schedule: Inputs, Tools & Techniques, and Outputs

The project schedule is an important input to this process. It is the actual schedule that needs to be controlled. Schedule data contains information related to the schedule that may need to be monitored to take actions to bring the project back on schedule.

Project calendar describes the working hours and days for the project. Work performance data has information like which activities have started, their progress, and which activities have finished. The other inputs of this process are project management plan and organizational process assets.

The key tools and techniques of this process are the performance reviews. Performance review is measuring, comparing, and analyzing schedule performance such as actual start and finish dates, percent complete, and remaining duration of work in progress.

The other tools and techniques include resource optimization techniques, modeling techniques, schedule compression, leads and lags, scheduling tool, and project management software.

In develop schedule process, these techniques are used for the first schedule to develop the project schedule, whereas, in control schedule process, these techniques are used to update the project schedule.

The key output of the control schedule process is the work performance information. This is represented in the form of schedule variance (SV) and schedule performance index (SPI).

As part of the control schedule process, the project team will generate forecasts, likely schedule for forthcoming activities and project as a whole. The other outputs include organizational process assets updates, change requests, project management plan updates, and project documents updates.

In the next section, let us look into a business scenario to understand this concept better.

Business Scenario: Problem Statement

In one of Janice’s project team meetings, her team is reporting the status of their assigned activities defined in the project schedule. About halfway through the meeting, a problem with the schedule is discovered as several activities are behind schedule.

After all activities for this phase of the project are reported, the overall schedule is determined to be progressing at about 75% of what had been planned. Janice has to figure out how she can get the schedule back on track. How can Janice go about solving this schedule problem?

Let us look at the solution for above problem statement.

Business Scenario: Solution

To aid in the decision-making process, Janice needs to schedule a follow-up meeting with her team to evaluate the impact of this delay on the triple constraint.

The delivery of the scope, budget, and schedule, along with quality expectations, resource availability, and risks have to be evaluated so that she can present a strategy for correcting the project’s schedule delay to the Project Sponsor.

Due to the team’s assessment, Janice can decide to add additional resources to the scheduled activities on the critical path. Before crashing the critical path, the team can identify a series of sequenced activities that can be rearranged and completed in parallel to free up more resources that can be re-allocated to the critical path activities.

By utilizing these schedule compression techniques, Janice was able to increase the project’s productivity rate to 95%.

Summary

Here is a quick recap of what was covered in this lesson:

  • Project schedule management includes the processes required to manage the scheduled completion of the project.

  • A project schedule defines the start and end dates of the project and the project activities. These activities are assigned duration and sequenced in a logical order.

  • Gantt charts and network diagrams are used to identify project activities and determine the relationships and dependencies between them.

  • Gantt chart displays the start and end dates of project activities, the overall project schedule, and the logical task relationships while network diagram is used to plot the activity dependencies.

  • Plan Schedule Management, Define Activities, Sequence Activities, Estimate Activity Resources, Estimate Activity Durations, Develop Schedule, and Control Schedule is the seven processes under Project schedule Management.

  • Schedule network analysis technique generates project schedule based on the estimates of schedule and resource requirements.

Conclusion

This concludes the lesson on Project Schedule Management. In the next lesson, we will learn about Project Cost Management

Find our PMP® Certification Online Classroom training classes in top cities:


Name Date Place
PMP® Certification 24 Aug -21 Sep 2018, Weekdays batch Your City View Details
PMP® Certification 25 Aug -22 Sep 2018, Weekend batch New York City View Details
PMP® Certification 31 Aug -28 Sep 2018, Weekdays batch Boston View Details
  • Disclaimer
  • PMP, PMI, PMBOK, CAPM, PgMP, PfMP, ACP, PBA, RMP, SP, and OPM3 are registered marks of the Project Management Institute, Inc.

Request more information

For individuals
For business
Name*
Email*
Phone Number*
Your Message (Optional)
We are looking into your query.
Our consultants will get in touch with you soon.

A Simplilearn representative will get back to you in one business day.

First Name*
Last Name*
Email*
Phone Number*
Company*
Job Title*