delays in construction projects

Predicting and Managing Delays in Construction Projects

Delays in construction projects can be a significant barrier to timely completion and the budget. However, with strategic planning and management, it’s possible to predict and mitigate the impact many of these delays.

Sources of Delays

Construction delays can stem from a variety of sources and most delays lead to an increase in costs:

  1. Design errors: They may have to be incorporated into the project if they are essential. Do not make it easy for the design team to make changes. Have a control system that manages changes as soon as they occur.
  2. Changes in the scope of the works: Try and discourage clients from making changes to the project. It is good for the design team to see the same principles applied to the client in cost control systems.
  3. Supply Chain Issues: Material shortages and labour shortages can halt progress. Maintain close contact with suppliers and monitor supply chains to anticipate disruptions.
  4. Weather Conditions: Unpredictable weather can cause delays. Use historical data and weather forecasts to plan ahead.
  5. Regulatory Changes: Stay abreast of legislation to forecast and prepare for regulatory delays.

Proactive Planning with CPM

One of the most effective ways to manage and predict delays is through the Critical Path Method (CPM). CPM is a step-by-step project management technique that outlines critical and non-critical tasks with the goal of preventing timetable overruns. Using CPM allows project managers to:

  • Identify Critical Path: Determine which sequence of activities has the least amount of scheduling flexibility and prioritise them.
  • Calculate Float: Understand how much delay can be accommodated without affecting the overall project timeline.
  • Early Starts: Whenever possible, begin tasks as early as the schedule allows to utilise the available float and buffer against future delays.

Utilising Float Wisely

The concept of ‘float’ or ‘slack’ is central to effective CPM implementation. It’s the amount of time that a task can be delayed without causing a delay to subsequent tasks or the project finish date. Delays can be avoided by:

  • Avoiding a last-minute Mentality: Don’t wait until the last minute to start tasks with available float; instead, use it to absorb the impact of unforeseen delays.
  • Strategic Task Management: Start tasks as soon as resources allow, even if they’re not on the critical path, to reduce pressure during the later stages of the project.

Avoiding delays

Despite predictive measures, delays can and do happen. Here’s how to manage them:

  • Evaluate how the delay affects the progress and cost of the overall project.
  • Make a decision as soon as a potential delay occurs.
  • Keep everyone informed about delays and the steps being taken.
  • Reallocate resources and reschedule tasks to get back on track.
  • Document all aspects of the delay for future reference or claims.
  • Monitor the claims and provisional sums to deliver the project.

Additional costs arising from delays

Delays cause additional costs, largely due to the site overheads. Therefore, if you sanction a delay, it will almost certainly have an additional cost.

Bear this in mind when you make a decision on the changes. Is it really essential?

Some contractors can exploit a delay in order to make a claim.


Delays in construction projects, while undesirable, are manageable with the right approach.

Understanding the sources of potential delays, utilising the Critical Path Method, and wisely using float time are essential for keeping projects on schedule.

Proactive planning, risk management, and open communication channels are the cornerstones of effective delay management.

By anticipating possible setbacks and strategically planning for them, project managers can navigate the complexities of construction schedules and deliver successful projects.

To read more about managing project risks and delays have a look at:
Scroll to Top