The Value of CPM Scheduling

CPM scheduling is an approach to project planning that can offer you significant cost and time benefits. In the construction industry, CPM is used extensively to manage complex and large projects. Yet, projects frequently experience time and cost overruns due to limited or improper planning and scheduling. By properly utilizing CPM scheduling, you can avoid these issues. This guide covers what CPM scheduling is, who uses CPM scheduling, the benefits of using CPM scheduling, and the differences between CPM and Gantt charts.

What Is CPM Scheduling?

The Critical Path Method (CPM) is a technique used to predict a project’s duration by analyzing what sequence of activities has the least amount of scheduling flexibility, also known as float. A CPM schedule is usually illustrated in graphic form and shows the network of activities required to complete a project. The critical path equates to the longest sequence of activities in the network which establishes a project’s overall duration.   

To fully understand a CPM schedule, it’s also important to understand the various elements of the schedule, such as:

• Activity: The individual activities of a CPM schedule must be performed to complete a project. Each activity represents an element of work that consumes time and may have associated resources. 
• Late start date: The late start date for each activity refers to the last possible moment the activity can start if you want to complete your project on time.
• Late finish date: Similarly, the late finish date for each activity is the latest an activity can end for the project to complete on time.
• Early start date: The early start date of each activity refers to the earliest date an individual project activity may start based on the schedule’s logic. The earliest listed activity’s start date is typically the project’s start date.  
• Early finish date: The early finish dates are the earliest each activity can finish based on the schedule’s logic.
• Project milestones: Project milestones are goals or events that denote particular points in time during the project, reflected in the schedule as an activity with no duration.
• Activity logic: Logic is referred to the relationships demonstrating the interdependencies between the starts and finishes of a schedule’s activities. This can be determined by contract requirements, construction sequence, physical limitations, safety concerns, available resources, and preferential activity relationships.

Who Uses CPM Scheduling?

Construction project stakeholders use CPM scheduling, such as property and business owners and managers of a business, construction contractors, fabricators, and equipment vendors. CPM scheduling is essential for construction schedule oversight and construction management and may be a requirement in construction contracts. Outside of the construction industry, CPM scheduling is used in many businesses to manage initiatives and projects of all types from software development, change management, process implementations, manufacturing, and resource planning.

Why Use CPM

Here are a few of the benefits of using CPM scheduling:

1. Saves time and money: A CPM schedule can help you save both time and money. A well-developed CPM schedule will provide a reasonable forecast of a project’s completion dates. It promotes the efficient execution of the work through improved coordination and resource management. The proper updating of CPM schedules can assist construction stakeholders in avoiding, tracking, and mitigating delays, preventing parties from incurring damages. Projects completed on time or early may also include monetary incentives.
2. Displays critical activities in graphical form: Your project may include thousands of activities that need to be completed. A CPM schedule gives you a clear view of your project’s critical activities that need to be performed to finish the project on time and avoid delays. The graphical display of these activities is an excellent communication tool between all the project stakeholders for the sequence of activities and the time required.
3. Helps with managing subcontractors: Construction projects typically involve multiple subcontractors working on different parts of the project that need to be coordinated. A CPM schedule can help manage the various subcontractors and their combined efforts. It helps identify when resources and materials will be required to perform work, what other work will be ongoing in the same area, and how long the work is expected to take.
4. Manages risks: A risk is an uncertain event that could impact your project’s objectives. With critical path analysis, you can identify and plan for problem areas that could arise throughout the course of your project. Using a quality CPM schedule in conjunction with risk management allows project teams to identify risk areas and develop alternative plans to avoid or mitigate the risks.

CPM vs. Gantt Charts

CPM and Gantt charts are both project management tools you can use to track the progress of your project and manage your activities to stay on budget and on time. However, there are some key differences between CPM and Gantt charts.

• CPM: CPM helps you identify the activities that are driving the overall project duration and outline the order of activities you need to meet to complete your project on time. The critical path shows the longest duration of time between your project’s start and completion. CPM helps you improve your scheduling decisions and estimates. 
• Gantt charts: You can use Gantt charts to track your activities against a timeline. Gantt charts show your schedule and monitor your progress and timing. 

Essentially, CPM displays the sequence of every scheduled activity to determine your project’s duration, while Gantt charts provide a timeline view of the project overall. Other differences between these two tools include:

• Purpose: The purpose of a Gantt chart is to give you a visual overview of your project’s activities and how your project is progressing. A CPM’s purpose is to provide a dynamic tool to recalculate your project duration as the work progresses, reduce total project costs, and help reduce timelines.
• Visual component: The visual component of a Gantt chart is also different from a CPM. While a CPM schedule may contain visual bars depicting the durations of activities similar to a Gantt chart, the CPM schedule’s logic differentiates it from a Gantt chart.
• Uses: While CPM can be used for detailed project scheduling, time estimating, and project management, a Gantt chart is used primarily for higher-level planning, progress tracking, and communication.  Most CPM software packages provide Gantt chart functionality.

Hire Spire for CPM Scheduling Services

At Spire Consulting Group, we customize our services to meet your construction project’s oversight and management needs. We are a full-service, fully integrated construction consulting firm with services that span the life cycle of a construction project.

Through our Project Management, Project Controls, and Construction Advisory service lines, we can help projects and companies avoid missteps in execution and potentially avoid construction claims after a construction project. We support both the proactive side of a construction project and the forensic analysis that can be necessary as a construction project ends.

Spire provides full-service planning and CPM scheduling services from initial project planning and schedule development through project execution and closeout that meet or exceed recommended industry practices. Contact us at Spire Consulting Group for our CPM scheduling services.

The content included in this article is for informational purposes only and does not reflect the opinions or recommendations expressed by any individual unless otherwise stated.