The Good, the Bad, and the Ugly of Construction Project Schedule

Category: Jobsite | By Paul Netscher | 4 minute read | Updated Jan 30, 2018
The Good, the Bad, and the Ugly of Construction Project Schedule

A project construction schedule should be drawn up for every project, and used to establish the quickest, most effective method for constructing the project. The schedule can take the form of a simple hand-drawn bar chart, or be an intricate, detailed schedule, using a proprietary software package, linking and resourcing the activities.

The schedule can be prepared by the project manager, or it may be delegated to a member of the team, who could be an experienced planner. It’s important, however, that the project manager controls the process, and ensures that the schedule not only meets the contract milestones but is also achievable with the available resources, that it reflects the chosen construction methods, it satisfies the client’s requirements, and that the project can be constructed in the safest and most economical manner without sacrificing quality standards.

The Good

1. The schedule

The schedule shows the team the goals/targets/milestones and when they must be met. It then shows the route that the team must follow – kind of like following a map to get to your destination. It provides the sequence of tasks to guide project managers and supervisors as to which activities they need to be working on, and which are the next ones they should be planning for. Without this map or schedule, you may find individuals in the team pulling and working in different directions, maybe even not knowing when the target must be achieved.

2. The dates

They provide the dates of when construction materials are required on the project site.

3. The resources

A resourced construction schedule allows you to plan the mobilization of resources such as equipment and personnel. You know how many of which type of resource you need and when. I’ve walked onto many projects and found that they either had too few, or too many, resources because the project manager didn’t understand, or wasn’t using, the project schedule.

4. The obligations

Many contractors see the schedule as an opportunity for the client to use it to bash and penalize them. I see it as an opportunity to ensure that the client meets their obligations (such as providing access and information) timeously. An approved project construction schedule is a valuable aid when preparing delay claims.

5. Progress

They can be used to monitor the progress of subcontractors and suppliers.

6. The subcontractors

Including the project schedule with the subcontractor's request to price documents and in subcontractor contract documents ensures that the subcontractor can have the necessary resources on the project at the required times and that they allow in their price for any specified interruptions and discontinuities in their work.

It reduces opportunities for them to misunderstand the construction project durations or resources required. This can avoid many of the reasons for variation claims and excuses for schedule slippage from our subcontractors.

7. The feedback

Importantly, the schedule provides feedback on whether the construction work is proceeding according to schedule and whether the project will be completed in time. When it’s detected that progress is slipping action can be taken to recover the slippage, which may include bringing on additional resources or working extended shifts.

8. Underlying problems 

Understanding that the project is slipping against the schedule and knowing why may give us a warning to other underlying problems that are costing the project money.

The Bad

The one thing that’s worse than not having a construction schedule is having a schedule that is incorrect. Yet, many construction schedules aren’t correct. Here are a few common mistakes.

1. The schedule isn’t resourced correctly

Or doesn’t take into account the available resources, or that the resources are required elsewhere on the project at the same time. It’s amazing how some planners don’t consider how you fit all the required resources into the available space, or whether the contractor or their subcontractor has the resources available.

2. The schedule doesn’t take cognizance of the client’s constraints

Such as: drawing issue dates, restricted working hours and the access to work areas. I have seen schedules with a start date that ignored when we would have site access or receive construction drawings. We have often had to interrupt our work-flow while the owner’s processes took priority. Processes that we knew before we prepared the schedule would occur. Processes and restraints that were outlined in the project contract document.

3. The schedule doesn’t allow for mobilization times

On some projects, there is a lengthy process to get resources to the site and inducted onto the project. I’ve had projects where the client’s mobilization process could take several weeks to negotiate before people were allowed onto the project. Anyway, people aren’t always simply available, ‘on a shelf’, when we need them.

4. Not taking into account the impact of the normal expected weather conditions

Wind, extreme heat, freezing temperatures, and rain can severely impact productivity and progress. The schedule should allow for the normal weather conditions which occur at that particular time in that region.

5. Allowing insufficient time for procurement

And manufacturing lead times. Sometimes additional time needs to be allowed for the design of these items, design approval, drawing preparation and drawing approval. Some items could take weeks or even months to procure.

6. Failure to take account of the impact of adjacent structures on the schedule

These impacts include cutting off access while the structure is being constructed, or structures that must be completed first because they are deeper or impact the structure in other ways. It could also include how access scaffolding or cranes on one structure impact the neighboring structure. Service and utility trenches, in particular, can have a major impact, particularly if they are deeper than structures, or pass underneath, or need to be connected to the structure.

7. Disregarding contractual completion dates

This seems obvious but is sometimes ignored.

8. Not allowing time for commissioning

Commissioning of some facilities can be lengthy and complex and depend on various sections of the work to be completed, as well as the completion and connection of the utilities.

9. Not including all the requirements to have an operational facility

Which may include connections of utilities such as power, water, and gas. It also includes obtaining all permits and permissions.

10. Not allowing for inspections and testing

These tests could delay the progress of the construction. In addition, the facility may not be occupied or used if the test results aren’t available or various approvals haven’t been obtained.

11. Failing to allow for design and drawing approvals

Sometimes the client or their team has to approve the design, drawings or even shop drawings. There should be adequate time in the schedule for this process, including time for the required corrections and re-submissions when required.

12. The construction schedule isn’t approved by the client in writing

The schedule forms a vital part to substantiate delay claims. However, if the schedule is not approved it is worthless. Some clients will avoid approving the construction schedule when they aren’t ready for the contractor and know that the approved schedule will support a delay claim against them.

13. The schedule isn’t communicated to the construction team

Sometimes this communication is done poorly and the project manager just dumps the complete schedule (sometimes with thousands of activities) for the whole project on the supervisor’s desk. Supervisors usually are only concerned with what must happen in their section of works for the next few weeks.

14. The schedule isn’t updated correctly

This can lead to a feeling of complacency and a belief that the project is on schedule when it isn’t. These updates must be done regularly.

15. The schedule isn’t modified to reflect the project changes agreed with the client

Frequently projects have changes and variations which are outside the control of the contractor. These variations should be agreed with the client and they should be included in a new construction schedule. These changes could be delays, additional tasks or reduced durations. This revised schedule must be agreed with the client to ensure that the project is working on a schedule that accurately reflects the latest project information.

16. The schedule doesn’t reflect the chosen methods of construction

This makes it difficult to accurately monitor progress and the schedule could be worthless should a delay claim arise.

The Ugly

Unfortunately, even the best construction schedules are worthless if:

1. The schedule isn’t used.

2. The updated schedule is ignored

With no action being taken to rectify the slippage and lost time.

3. Manipulating schedules

Contractors deliberately manipulate the schedule to hide that they are behind schedule.


A construction schedule is a valuable tool to plan and monitor construction projects. Unfortunately, sometimes these schedules have errors that can provide misleading information. It is important that the schedule is prepared properly, taking cognizance of all aspects of the project site, the type of structure being built, the terms of the contract document and the local weather conditions. Of course, the schedule must be realistic and not something that is forced to fit the client’s milestones which might not be realistic!

But, the schedule shouldn’t just be a document prepared only for the client and our managers, which is then left and forgotten in a drawer. It needs to be referred to and used to provide direction on the project. It should be used to monitor progress. Where necessary it should be changed to reflect the changes to the project that have been agreed with the client.

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