Critical Path Method Scheduling in Construction

Advantages Of Using The Critical Path Method Scheduling in Construction

The critical path method has been around for almost 70 years. In 1950 engineers James E. Kelley Jr. from Remington Rand and Morgan R. Walker from DuPont developed a project scheduling method that became known as the critical path method (CPM). Now construction companies of all sizes use this method every day. Read on to find out more.

What Is The Critical Path Method Scheduling?

Are you wondering what is a CPM schedule in construction? In simple terms, it’s a way to plan out projects step-by-step. Although you can apply it to any industry, it’s especially important in construction because it adds more prediction It list ally. The Critical Path Method is also called CPM or Critical Path Scheduling. With this technique, users can control and plan their projects. It’s incredibly popular in the construction industry. One of the most crucial elements in calculating the minimum time for completion includes estimating the start and finish times for each activity and the project itself.

Critical Path Basic Steps

The basics of the critical path method (CPM) are

• • List All Activities
  • Create Activities Logic
  • Determine CPM or Longest Path of Project

Each project is separated into tasks that need to be completed. Tasks get listed based on the earliest start and finish date. Some projects have multiple paths, and others can run parallel. The path with the longest duration is considered the critical path. Keeping a project on schedule means making sure there are no delays. If there are delays, adjustments need to be made. Besides basic steps there are specific requirements to be aware of.

Requirements for a CPM scheduling

It’s helpful to know the specific requirements for CPM scheduling. It’s not just a list of activities with planned dates. A CPM schedule has certain conditions. These are:

• • Calendars – You’ll need to plan your calendar around the project schedule. Many jobs will run on a five day work week at eight hour days. If you have a separate crew working four days at 10 hours each day, it’s best to have a different calendar to keep things organized.
  • Logics – A bonafide CPM concept schedule has activity dates set around predecessor activities (except the first activity). Also, each event has successor activities except for the last one.
  • Constraints – are useful if they’re used for valid reasons such as an interim date constraint representing an external driving force or milestone date. It’s important not to overuse constraints, so the longest durations are represented correctly.

• • Relationships and Lags – Best practices for using SS Start-to-Start and/or FF Finish-to-Finish relationships is when work runs concurrently. And lags shouldn’t be used on a waiting period or to model work.

Additional Requirements For CPM Scheduling

• • When laying the path out, activities are listed in their sequence. Which activities come first, and which one follows and in what sequence. What’s the least amount of time the entire project will take?
  • When estimating the time each task takes, if one or more tasks experience delay, the entire project will need more time.
  • One single project can have multiple critical paths – which, when complete, so is the project. Any delays in sub-projects will result in the project’s delay.
  • The advantage of Critical Path Scheduling is that it includes all the needed data into one plan. That plan represents sequences, duration, interrelationships, completion date and most importantly the longest path of project.

Overall, the critical path method is utilized to visualize and determine a project’s duration. In its simplicity, CPM analyzes, plans, and schedules out complex projects.

That’s why utilizing a CPM program in construction helps calculate the length of projects and aids in profitability.

Importance Of Critical Path Method In Construction

Creating a critical path is composed of these important six steps.

1. 1. The identification of all activities
   2. The sequence of activities are established
   3. A network is created
   4. Completion time is calculated by program
   5. Critical path is identified
   6. Along the way the CPM diagram is updated

With each task laid out with the start and completion dates, all shareholders can see and use that information when it comes to their duties within the project. Additionally, you will see which are dependent on others, whether they are complete and approved, and what’s running late.

With CPM you can also track early the start and finish dates as well as the late start and finish dates.

If you consider that the project’s length has a significant effect on the cost and bidding, you can see why this process is so vital in construction.

Tracking Multiple Activities

Here’s an example of one project that contains four different activities.

• • Activity A will take two months.
  • Activity B also will take two months but cannot start until A is finished.
  • Activity C will take one month and is interdependent of both A and B.
  • Activity D takes two weeks and is interdependent on all the above.

That’s where having an accurate CPM is important. Plus, you may be working with many different subcontractors including

• • Plumbers
  • Roofers
  • HVAC
  • Electricians
  • Masons
  • Carpenters
  • Painters

So it’s essential to know when their tasks need to be started and completed. Plus, if there are changes with one sub, it’s vital to see how it will impact the scheduling. Let’s learn more about some of the main advantages.

Advantages & Benefits Of Critical Path Method In Construction

Here are the most significant reasons you’ll want to use this method for your construction projects.

1. 1. You’ll have a complete long-term view of the entire project. You’ll be able to see which activities can run parallel to each other. That will help in seeing when and if you can take on other jobs.
   2. Every step has detailed planning and scheduling. Having every step listed makes sure nothing is forgotten so you won’t have any surprises later on.
   3. All stakeholders will have needed comprehensive data. So, they’ll know what’s expected of them and delivery times. And, it can help teams work better together too.
   4. You can have more standard documentation and communication. With the CPM as your guide, everything revolves around it because it shows all activities, including their outcomes in diagram form.
   5. You’ll know the most crucial elements in the project to focus on. That helps management know what’s critical. Plus, it helps the project managers in identifying the vital elements in the project.
   6. You’ll be able to see the cause and effect of any changes. If something has to be rescheduled, you’ll see how that affects the other tasks.
   7. You can plan more economically and meet completion dates. With solid start and completion dates, you’ll have a better chance of meeting your projection targets.

Let The Critical Path Method Help Your Business

As you can see, there are a lot of items to track. That’s where it’s vital to use software. Just like any software, it’s essential to put in the correct information – otherwise, the calculations will come out incorrectly.

Ariabuild’s professional and experienced schedulers have the technical expertise, and real-life construction experience in preparing initial, bid, baseline and construction schedules. We can help you save cost and time and control you project timeline and budget from concept to completion phases.

Having a CPM schedule is vital. Whether you’re a small contractor or a large global construction firm, the critical path method is vital for success in any sized project. From residential home building to large government jobs, you’ll feel more confident in your bidding and accurate estimation of your project’s completion when you take advantage of this method.

If you’d like to know more about our CPM services and how Ariabuild can help make your business more profitable, contact us today.