Project Scheduling & Tools

1. Activity Sequencing

Now that you’ve identified the resources needed and estimated how long you think the project will take, we can begin to look at how we schedule the project and sequence each of our activities. In other words, we can look at the order in which we need to do everything for our project.

One important thing to note: we are addressing this as a sequential process (work breakdown structure or WBS and schedule), but often, these tasks already have a head start because some of the work was done when the project charter was created. Also, many project managers might work on the scope management plan at the same time they create the WBS. So, while we present this as a linear process to help with learning the concepts, project management is rarely linear.

Now, we will be working on the scheduling aspect of the PMP.

Planning Phase Component	Addresses	Document	Document Purpose
Scope and scope management	Defining exactly what work is required (and what is not) to deliver the project’s objectives	Scope management plan	Outlines how the project scope will be defined, validated, and controlled to prevent scope creep
Work breakdown structure (WBS) and scheduling	Breaking the project deliverables into smaller, manageable components and estimating the time needed to complete each activity	WBS and schedule	The WBS breaks the project scope into manageable components, serving as the foundation for planning, estimating, and assigning work
Identify the resources needed	Determining the people, equipment, and materials required to complete project activities	Resource Management Plan	Created to document the type, quantity, and timing of resources so they can be acquired and managed effectively
Determine costs	Estimating the costs associated with the resources needed for the project activities	Project Budget and Procurement Management Plan	The project budget documents the costs of the project. The Procurement Management Plan documents goods and resources needed to be obtained for the project
Communication	Determining how project information will be shared among stakeholders (remember, you identified stakeholders during the initiation phase!)	Communication Management Plan	Created to ensure the right information is delivered to the right people at the right time using the right methods
Risk assessment and management	Identifying potential events that could impact the project, analyzing their likelihood and impact, and planning responses	Risk Management Plan	Created to record identified risks, their characteristics, and planned responses so they can be monitored and managed throughout the project

The important thing about scheduling a project is that some tasks must be done first before others can begin. This is referred to as sequencing tasks. Sequencing tasks is organizing tasks in order of their dependencies.

For example, in our spa app example, we must complete the development of the app before testing can begin. These are called predecessors. Let’s look at the different kinds.

• Sometimes, your project will depend on things outside the work you’re doing. These are called external predecessors.

EXAMPLE

If we were planning a wedding and one of the tasks we needed to complete was to decorate the reception hall, then we would need to ensure that the reception hall was ready and available for us before we could begin decorating. This might include checking that the space is clean and empty and that we have access (available). Therefore, decorating the reception hall depends on the hall being ready and available as an external predecessor.

• Discretionary predecessors are usually process- or procedure-driven or best practice techniques based on past experience.

EXAMPLE

In the wedding example, Steve and Susan want the bridesmaids to arrive at the reception before the couple arrives. There’s no necessity; it is just a matter of preference.

• Another example might be that you can’t address an invitation that hasn’t been printed yet. So, printing invitations is a mandatory predecessor required before addressing them. Mandatory predecessors are the kinds that have to exist just because of the nature of the work.

Now that we understand predecessors, we can look at the various ways we can optimize our schedule.

terms to know

Predecessors

The things that must be done first before others can begin when completing a project.

External Predecessor

Outside elements that must be completed before a task can be started.

Discretionary Predecessor

Process- or procedure-driven element that must be completed before a task can be started.

Mandatory Predecessor

Something that must be completed before a task can be started because of the nature of the work.

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2. Tools for Project Scheduling

Do you remember when we talked about the triple constraints on a project? Triple constraints consist of scope, time, and cost. Since time is an important part of project management (and can cost money if not done correctly!), there are a number of tools that can be used to track time (schedule). The goal of scheduling tools is to ensure there is a clear roadmap for the project team. Let’s take a look at those tools now.

2a. Gantt Charts

One schedule optimizing tool many project managers use to determine the predecessors of a project is a Gantt chart. A Gantt chart is a type of bar chart, developed by Henry Gantt, that visually illustrates a project schedule. Gantt charts are easy to read and are commonly used to display scheduled activities. These charts display the start and finish dates of the terminal elements and summary elements of a project.

hint

Terminal elements can be thought of as the lowest-level tasks (subtasks) in the WBS, while summary elements refer to higher-level tasks and milestones.

Some Gantt charts also show the dependency relationships (i.e., precedence network) between activities.

The advantage of a Gantt chart is that it allows you to see the following:

• The start and finish dates of tasks
• The duration of a task (how long you expect something to take)
• Dependencies or predecessors (what must be finished before something else can begin)
• The progress of the project

Gantt charts show all the key stages of a project and their duration as a bar chart, with the time scale across the top. The key stages are placed on the bar chart in sequence, starting at the top left corner and ending at the bottom right corner. A Gantt chart can be drawn quickly and easily and is often the first tool a project manager uses to provide a rough estimate of the time that it will take to complete the key tasks. Sometimes, it is useful to start with the target deadline for the completion of the whole project because it is soon apparent if the time scale is too short or unnecessarily long. The detailed Gantt chart is usually constructed after the main objectives have been determined.

Let’s look at an example Gantt chart for our spa app project.

EXAMPLE

As you can see, the weeks are listed at the bottom of the chart. This is the duration we’ve already estimated the tasks will take.

“Design” (task 2) must be done after “Planning and Requirements” (task 1). Likewise, “Development” can’t be done until “Design” is done.

Do you remember our example in the last challenge on making a PB&J sandwich?

Let’s take a look at the WBS for that:

EXAMPLE

think about it

Do you see any tasks that could be done at the same time? What tasks do you see that are dependent upon each other?

• Dependent tasks: “2.1 Apply peanut butter” and “2.2 Apply jelly” must be done BEFORE we can combine the sandwich. So, these two tasks would be dependencies.
• Independent tasks: These are tasks that can be done in parallel. Suppose your knives and plates are stored right next to each other. Because of this, “1.4 Get a knife” and “1.5 Get a plate” can be done at the same time, in parallel.

Identifying tasks that can be done at the same time saves time on the project schedule.

This process allows us to see visually, based on the activities and durations we’ve identified, how long a task will take.

term to know

Gantt Chart

A type of bar chart that illustrates a project schedule.

2b. The Network Diagram

Another way project managers can optimize a schedule is by using a network diagram. Many project managers use network diagrams when scheduling a project. The network diagram is a way to visualize the interrelationships and dependencies of project activities. Network diagrams provide a graphical view of the tasks and how they relate to one another. The tasks in the network are the work packages of the WBS. All of the WBS tasks must be included in the network because they have to be accounted for in the schedule. Leaving even one task out of the network could change the overall schedule duration, estimated costs, and resource allocation commitments.

The first step is to arrange the tasks from your WBS into a sequence. Some tasks can be accomplished at any time throughout the project, while other tasks depend on input from another task or are constrained by time or resources. Additionally, there are times when tasks can be done in parallel, as demonstrated below in the wedding project example.

EXAMPLE

Let’s look at a wedding planning project. In the image below, you can see that the arrows represent how the tasks are connected and the order in which they must be completed. In this case, the calligrapher must be picked before the invitations can be addressed, and both of those things must be done before the invitations can be sent. However, we can pick the calligrapher and pick the printer, design the invitations, and print the invitations at the same time (in parallel) but before the invitations are addressed.

The network diagram provides important information for the project team. It provides information about how the tasks are related, where the risk points are in the schedule, how long it will take to finish the project, as currently planned, and when each task needs to begin and end.

In our wedding planner example, Sally would look for relationships between tasks and determine what can be done in parallel and what activities need to wait for others to complete.

term to know

Network Diagram

A way to visualize the interrelationships and dependencies of project activities.

2c. The Critical Path

The critical path (also referred to as the critical path method) is the longest path through the project, and any delays along it will delay the completion of the entire project. Identifying the critical path helps project managers prioritize resources and ensure they are monitoring progress on tasks that are time sensitive. There are a few other reasons why the critical path is important:

• It defines the duration of a project: It helps determine the minimum amount of time and the maximum time a project might take.
• It highlights project priorities: If something is on the critical path, the project manager knows that any delay with those tasks will delay the project. So, they can put resources, such as human resources, to complete those tasks.
• It improves resource allocation: It can help project managers put resources on the project exactly where they are needed to keep to the schedule.
• It grants control: It allows project managers to track progress against what is expected in the critical path and see if tasks are at risk of being delayed.

The critical path is based on the idea that some tasks must be completed before others can begin. Thus, while some tasks can be sequenced with much flexibility, critical path tasks are locked in by task relationships. A critical path diagram is a useful tool for scheduling dependencies and controlling a project. To identify the critical path, the length of time that each task will take must be calculated.

Project managers often use software such as Microsoft Project to determine the critical path, although it is possible to manually calculate it, which, however, is out of the scope of this course.

learn more

Want to learn more about how to calculate the critical path? Visit this website to see the steps for calculations. www.projectmanager.com/guides/critical-path-method

Another helpful element of calculating the critical path is that it allows you to determine slack time. Slack time is also called float; it is the amount of time tasks can be delayed without delaying the overall project.

Keep in mind that the goal of a project manager is to maintain the project schedule. Optimizing the schedule is important, and this can be done by understanding the critical path and slack time.

Activities such as developing the Gantt chart, network diagrams, and the critical path help us keep the schedule optimized. This allows us, as project managers, to see all of the activities and to not only stay on schedule but also save time when needed.

Much of the work related to scheduling, though, is done using software that helps us schedule and sequence our activities.

Project planning software usually does the following:

• Handles developments and changes to the Gantt charts and network diagrams and calculates the critical path
• Produces schedules and budgets
• Integrates project schedules with the calendar, allowing for weekends and holidays
• Creates “what if” scenarios for contingency planning and updating
• Checks for overscheduling of individuals and groups

Now that we’ve addressed sequencing as it relates to project scheduling, let’s take a look at how we might consider the assignment of resources to our project.

terms to know

Critical Path

The longest path through the project, and any delays along it will delay the completion of the entire project (also referred to as the critical path method).

Slack Time

Also called float, it is the amount of time a task can be delayed without delaying the overall project.