Construction Scheduling

Is CPM Scheduling Critical in Construction?

Is CPM Scheduling Critical in Construction?

Many of our customers are looking for a quick and easy way to develop a construction schedule. There are many complex software programs on the market today (and the list keeps growing) that offer resource planning, cost-loading, s-curve reports, earned value metrics and more.  However, many of our customers in construction do not need all of those features –they are just looking for a simple, easy-to-use tool to plan out the timeline of their projects.

Yes, critical path scheduling is truly “critical” in construction so that you can see the impact of changes as they occur throughout a project’s duration. Some people do not know the steps involved with creating a CPM schedule and how easy it can be to use –especially to your advantage. I’ve outlined the steps below.

How to Develop a Critical Path Schedule

To develop a critical path schedule, you just enter tasks with their planned duration (usually in days) and establish predecessor and successor relationships between tasks in a scheduling program. Let the scheduling software work for you! So many people try to develop a schedule by entering the start and finish dates for each activity. That is NOT how you develop a CPM schedule or a good schedule! We suggest no open-ended activities except for the Project Start and Project Completion activities in your schedule. Once you hit a button to “schedule” your project plan, a value called float or slack is calculated for each task identifying how many days late it can be before impacting your project as a whole.

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Critical Path Schedule for a construction project

The critical path settings vary depending on the scheduling application that you use. Tasks are critical usually when the float or slack value is less than or equal to 0. This indicates the number of days that need to be made up to get the project back on track. For instance, if your float or slack is equal to (-2) for activities on the critical path this means that you have to make up 2 days in your schedule to meet your project finish by date. 

Use Templates to Develop a Project Plan

It does not have to be hard to create a schedule for your projects. We always recommend starting with a template so that you are not starting from scratch every time. If you have repeatable steps in your projects –even if they are generic –use them to help you with the planning process. It is much easier to edit tasks, and the process can act as a checklist to make sure you are not missing anything. In a template, you can save as much information as you know such as a Work Breakdown Structure (WBS), task descriptions, durations, logic and more. It can take a few minutes rather than hours to develop your project plans.

Baseline a Project Plan before Updating

Now one of the most important steps that many people skip is the baselining process. If you do not baseline a schedule, when you update your project you will overwrite your planned start and planned finish dates with actual start and actual finish dates. In fact, it will appear as if you are always “on-schedule” when you are not. By baselining you can create visual views to see where you thought you would be on the project and to where you are. Baselining in a software tool is as easy as hitting a button, so don’t skip it!

Updating a Project Plan

I was just speaking with a company who said, “We always develop a schedule but on one ever updates it.” That happens far too often for many who do not take a disciplined approach to scheduling. You need to update the schedule on a regular basis on a frequency that makes sense for your projects. It may be weekly or monthly depending on how long your projects last. Some of our customers in the energy industry managing nuclear power plant outages update their schedules hourly!

It can be a daunting task to get updates into your project plan --that is why so many people skip this step. However, it can be an easy process with a little bit of preparation. If you develop a view specific to the fields that you want to update, it makes it simple for anyone to provide the updated information. For instance, we suggest a simple view like you see in the screenshot below. We try to make it look as simple as an Excel spreadsheet (but it is not!).

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Updating View

Use Reports to Communicate with the Project Team

Throughout the duration of a project, it is important to make sure to share the information with the team.  During a team meeting, you walk through progress information and review any issues or risks on the project. You can generate simple reports to share during the meeting. Many people use a report called a look-ahead report i.e. a 2-week look ahead report. This is a report that is a filtered list of activities about the period in review. You can also use a bar chart report to view slippage in your project plan in a graphical format. In the screenshot below you can visually see the impact on the schedule as a whole when the second activity did not start on-time. All of the tasks that are dependent on it are affected. Again, the idea is to capture what’s happening so you can work as a team to resolve issues before they happen.

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Tracking View

Why use a CPM schedule?

The construction schedule is meant to be a business intelligence tool to the project team. It is intended to bring the foresight of issues before they happen. It is a communication tool to discuss what’s going on in a project with the team and stakeholders. It is a very critical component of construction projects and doesn’t have to be that hard with a little discipline and planned approach. 

If you’d like to learn more about our VPO project scheduling tools, please visit our website at for more information.

Any questions or comments, please email me at

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