Introduction :

The CPM schedule is a well-organized approach to project planning which can provide valuable benefits in cost and fulfillment time of many projects. The concepts were first revealed at DuPont, and polished by the United States Navy in the development of the Polaris Missile.

They can be implemented in various projects, from manufacturing and production to surgeries and conventions. CPM schedule has found extensive use in the construction industry, where cost and time overruns and often experienced. The proper use of CPM schedule techniques can help you avoid such issues on your own projects.

You have plausibly heard of CPM Schedule at some end. While you feel like you don’t need to bother yourself with it, there’s reasonable possibility that you will be up to your armpits in the CPM Schedule once that big project gets rolling. It’s True, Primavera P6 does run all kinds of fancy algorithms when you hit F9 button but owning at least necessary information of how CPM Schedule works are going to help you go far away as a good planner/scheduler.

What is CPM Schedule?

First things first: CPM Schedule stands for Critical Path Methodology. The Critical Path Methodology is a mathematical algorithm for scheduling project activities in Primavera P6.

In simplistic terms, I like to say that “CPM schedule assigns dates to activities.” But it also does a bit more than that as well.

CPM Schedule delivers three distinct pieces of information:

• CPM schedule assigns dates to project activities.
• It also calculates your project’s Finish Date.
• CPM schedule reveals your project’s Critical Path.

That’s some great stuff you will want to understand about your project.

Primavera P6 uses the Critical Path Method to schedule work activities and operations.

Here’s how.

Essentials and Foundation:

As discussed, CPM Schedule is a mathematical method and being so, and it has a record of pre-requisites to meet before it works its magic.

Before you implement the Critical Path Method (or run the scheduler in Primavera P6), here is something you need:

• A list of Activity
• Duration estimations for each and every activity in the list.
• Linkages between activities that define the order of execution.

The first two items are honestly visible. But it’s those linkages that play a significant part in the process. It’s linkages that convert the list of activities into a network of inter-dependent nodes that may have multiple paths through from start to finish.

The  Process Scheduling:

So you must be thinking how does the whole scheduling thing work, right?

The CPM Schedule process runs through your project activity by activity twice.

It gets starts with the initial activity and moves forward-this known as the Forward Pass. For every activity, it specifies or calculates that activity’s Early Dates.

Early Dates is the most favorable start and end dates for your project’s work activities.

Then the Backward Pass comes next. In this, you will start at the last activity in your network and moves backward allotting dates to all activities, until you approach the first activity in the network. These dates are Known as–you guessed it–the Late Dates.

Late Dates describe the latest your activities that can start and finish without extending the project’s finish date.

It sounds confusing, but you NEED to sets of Dates-both Early and Late – to come up with a project’s CPM Schedule.

Your Critical Path analysis:

To find a project’s Critical Path, you need to calculate Total Float for each activity. Total Float is also the contrast between the Late and Early Dates.

The Total Float = Late Start – Early Start (or Late Finish – Early Finish), Total Float is a ratio of how much scheduling flexibility an activity has.

Therefore, after Total Float is estimated for each activity, you will find that many activities have Total Float = 0d. And it is those 0d-Float activities that determine your project’s Critical Path. Just follow the path of activities where Total Float = 0d & also your Critical Path will show itself.

Apply CPM Schedule:

You all know that knowledge is power. Well, I  would also like to say that applied knowledge is power.

Although the details of CPM Schedule seems like it’s only for academics, arming yourself with it will assure you are not caught off-guard when a client queries you for early dates or why an activity is critical. Then, you can impress them with your own backward pass calculations of CPM Schedule.