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Project Scheduling

Top 8 Reasons for Delays in Construction Projects

Construction projects are one-off strives with many distinctive features like a long period, abominable environment, complicated processes, financial intensity, and such technological and organizational complexity creates enormous risks which resulted in the form of delays in construction projects in completion and cost overrun.

In construction, the delay can be defined as the extra time required or incurred either beyond the stipulated completion date or beyond the date that the project stakeholders agreed upon for the completion of the project.

Successful completion of the project on time is an indication of the efficiency of all stakeholders involved in the project but the construction process is subject to many variables and unpredictable factors, which result from many sources.

The following are the main reasons for delays in construction projects. With proper management, technical knowledge, and techniques these delays can be reduced to a minimal level.

1. Change In Project Scope

Change in project scope can produce project delay

The scope of work in a construction project defines as the deliverables that are expected at the end of a project.

Poor scope definition at the start can be a result of cost overrun and time delay of any construction project. Therefore all the project plans, schedule, cost, and quantity estimation, procurement and quality mechanism are usually calculated from the initial project scope.

Change in project scope could be due to poor initial project scope definition, miscalculation of inherent risks and uncertainties, project funding issues, change in the interest of the client or force majeure, etc.

This could result in variation order that successively could lead on to vary in project deliverables, budget and/or even the entire project team.

Thus, any modification/change within the project scope throughout execution will cause the whole initial project set up to be revised the i.e revised budget, construction methodologies, construction schedule, procurement plan, quality assurance plans, etc which will lead to more time, resources and cost against the initial baseline to complete the works.

To attain the proper control on change in project scope, it is necessary to first identify the fact that change is inevitable in the project and could equally be beneficial to the entire project’s success. Thus the foremost necessary factor to try and do is to integrate a correct change in scope management set up such a proactive approach that might be adopted involving the project stakeholders and incorporating their needs throughout the project lifecycle.

During the initial planning phase of the project, it is important to identify the key success factor in conjunction with the client and establish key performance indicators in the form of milestones that will calculate the success for achieving the project scope.

Similarly, to avoid disputes, it’s necessary to perpetually ask for approval for changes from the sponsor and communicate changes in an exceedingly timely manner and for extremely evolving modification in the project during construction, the scope might be frozen to focus on the expected future deliverables.

2. Project Complexity


The project complexity can be a major factor for time delay and cost overrun.

Complexity might be outlined in terms of the scale of the project, most mega construction projects i.e dams, motorways, skyscrapers, nuclear power stations, etc. tend to possess a comparatively long implementation duration in comparison to the small construction project i.e residential houses, shops, non-commercial buildings, etc.

This might result in a change in material prices, changes in exchange rates, and inflation rates such that the initial proposed/allocated budget needs to be supplemented for the project to be completed.

The result might be an increased cost and long chains of negotiation which eventually will cause a delay in the overall duration of the construction project.

Similarly, projects with a high degree of complexity usually result in complex plans, schedules, and estimations.

If proper care is not taken the ability to exclude these complex aspects of the project, it would lead to the variation orders, resultantly would lead to time delay and cost overrun.

This could lead to delays and costs.

Also, project quality might even be outlined in terms of the variety of stakeholders with totally different interests and an extended chain of communicating with slow feedbacks. Therefore desegregation of their interest might take plenty of valuable time and resources that once unnoted might lead to conflicts and disputes, thus affecting the project in the context of delay and cost overrun.

Extensive planning is required to eliminate or reduce the impact of time delay and cost overrun by calculating/incorporating every major aspect of the project, detailed WBS, major milestones, project stakeholders, the methodology to be adopted, and delivery time to the client.

Managing complex projects need experience, expertise, and exposure. Thus Project needs its goals and scope to be defined, based on the client requirements. To keep the project on track and ensures doing solely the task that’s aimed. It is thus vital to create an honest team with project success interest inside to attain this.

3. Inadequate Planning


Planning is one of those aspects that affect the outcome of so many different things in life.

The term planning is being used in many ways and different contexts but it can be explained as planning the human and machinery inputs in a way that to avail the maximum output is called planning.

To plan a project means to identify/distinguish the tasks or work activities to be performed to obtain the desired outcome in minimum time and cost, this starts the day the idea to put up a project is conceived.

There are several professionals and workmanship involved in the construction process, so a planner has to make sure that every aspect of these is already incorporated in the planning process to obtain the maximum outcomes and best results.

During the construction phase, the planning means calculating all the plants, types of equipment, materials, suppliers, human resources, time, and cost required to complete the curtain phase of the construction.

During the construction process, there are certain activities/tasks which require time to settle or to perform the successor activity i.e concrete curing time, the time required for laying the other layer of concrete, prime coat required to settle, etc.

A planner or responsible person should have adequate knowledge of these settling times to ensure while planning.

With proposed planning deliverables and inadequate planning outcomes in delayed project completion, cost overruns, and poor quality work among other things.

It is so necessary that the team responsible for the project accurately and plans before the execution of activities to confirm the sleek flow of works, the value of money, and timely completion.

4. Impropriate Project Schedule

Scheduling is a method in which the work activities are arranged in a sequential logical order to achieve the project within the stipulated time frame.

Scheduling shows not only the logical order in which the activities are intended to be carried out, but also enables the participants of that project to monitor progress. In addition, the schedule depicts the project’s future work while providing historical data that could be useful in analyzing the past.

This most common type of scheduling to the portrayal of bar chart; either hand-drawn or, more likely nowadays, computer- generated using commercially available project planning software i.e Oracle Primavera P6, Microsoft Project, Asana, Ceiton, EnQuire, and Huddle, etc.

To properly lead and work on a project the scheduling is an integral part to maximally utilize the available manpower and resources.

Scheduling requires immense technical knowledge, the sequential order of construction activities, accurate logical relation between the activities and resources required for each activity.

With impropriate project schedule the precious project resources will be diverted to the activities which are not critical and as a result, the critical activities will suffer and the delay will occur in over the construction time frame.

To mitigate the scheduling problems the scheduler should have the technical knowledge base that is relevant to the project, the scheduler should be able to accurately understand the scope of the job and work around this in an effective manner.

He should have strong knowledge and grip to properly identify how each event within the project should pan out. Strong knowledge of Contracts, Engineering Estimates, Bill of Quantities, Engineering Drawings, Project Scope, Nature of the Works, Clients requirements, and relevant documents enables the scheduler to develop a comprehensive Work Break Down Structure (WBS) with all the activities, resources, costs, constraints and risks involved in the project.

A scheduler should have hands-on experience in a variety of modern project management software i.e Oracle Primavera P6, Microsoft Project, Asana, Ceiton, EnQuire, etc. Knowledge of Oracle Primavera P6 is preferred as it is being used in most industries as an effective project management tool.

The Oracle Primavera P6 is a comprehensive/broad, scalable, project planning, scheduling, and monitoring software, built on Oracle or Microsoft SQL databases for organization-wise comprehensive project management.

Primavera required trained experienced experts to operate as it’s not user-friendly software. But if someone wants to share Primavera P6 information with all the project stakeholders or team members and make it accessible to view and print or analyze the Primavera file (.xer) I strongly suggest ScheduleReader software.

ScheduleReader is an easy-to-use project viewer that gives the liberty to view, print, and analyze the direct Primavera P6 (.xer) files dynamically without going through the tedious process of generating the .pdf report from a Primavera professional. This software is also available to download in a 15-day free of charge, trial period.

It also allows you to see through the .xer file which makes it more accessible to all the stakeholders of the project and saves countless hours for the consumers. ScheduleReader interface looks very similar to Primavera but it’s clean and more user-friendly with all the tabs on top of the screen are aligned with Primavera’s default screen.

The Gantt charts look more stylish like Microsoft Project with a smooth display of activities, WBS, Milestones, and relations, etc. In ScheduleReader one can update the progress of activities and it will generate .xlxs file which directly can be imported in Primavera P6 software and upon scheduling it will schedule the work plan automatically.

Furthermore, one can also compare the progress with baseline by directly importing the .xer file in SchduleReader, and similarly like Primavera P6, four (4) baseline files can be added and compare to check the deviations if any in the work plan for better monitoring of the works.

5. Design Variation

Design variation/error is a major factor for delay and cost overrun in a construction project.

It is vital to notice that accurate representation of the employer’s demand and therefore the blueprint to achieving better technical input to project execution are typically sorted out base on project designs and specifications.

A faulty design means insufficient or inaccurate project deliverables during the execution of the project.

This will lead to the incorrect application of techniques in achieving successful results, such as because the actual execution section of the project unfolds these design errors in the later stage, attempts to correct it will cause a time delay and value cost overrun.

Secondly, all project costs, time, and quality estimation based upon these designs and changes in the design in a later stage will eventually cause the cost and time variation orders.

Achieving accurate design entails properly documented communication with the design teams of all stakeholders and integration of a design method that’s accurately planned, giving sufficient time for modifications, corrections, extensive investigation, reviews, and final approvals.

Similarly, effective project planning, controlling, and monitoring should be established to enhance project performance throughout the project life cycle.

6. Inaccurate Engineering Estimate

Before the execution of any project, the Employer assesses the initial size of the investment required to incur in the project by an Engineer estimate.

Based upon the Engineer Estimate all economic benefits and calculations are done that’s why the engineer estimate needs realistic cost figures.

A detailed investigation study, extensive design expertise, a clear scope of work, accurate quantity calculations, and proper planning with complete modus operandi is required to obtain the Engineer estimate.

Inaccurate/error in estimation will cause the cost overrun and subsequently will result in a delay in the duration of the project.

Achieving the accurate Engineering estimate required the quantity take-off engineer to extensively approach all the stakeholders of the project to obtain all the relevant information required to calculate the cost.

Similarly, effective communication with design sections and the Client is required to enhance the chances of the most accurate engineering estimation.

7. Inefficient Material and Equipment Management

Industry construction site labor people worker wire steel bar

Material and equipment management is also an integral component during the execution of the project.

Both represent a major cost expense in any construction project and material accounts for 60% to 70% of the direct cost of a building project.

So minimizing the total procurement/purchase or rental cost can hugely influence the overall cost of the project.

The materials and equipment management system commits to make sure that the appropriate quality and quantity are selected, purchased, transported, delivered, and handled on-site in a timely manner and at a reasonable cost.

Poor management can also result in large and avoidable costs during construction and delay in the completion of the critical works due to the non-availability of the material and equipment at a crucial time.

Good management in construction must vigorously pursue the efficient utilization of the material and equipment.

Material and equipment handling, which includes procurement, inventory, shop fabrication, and field servicing, requires special attention for time-saving and cost reduction.

The use of modern technologies and innovative ways has created potential wholesale changes in construction technologies.

With the right coordinated planning, evaluating the quantities and requirements, sourcing, purchasing, transporting, storing, operation, and maintenance of the equipment, minimizing the wastage and optimizing the profitableness by reducing the price and saving them valuable time.

8. Improper Post Execution Phase Management

Finally, the closure or post-execution phase of any construction project is an extremely crucial stage that contains several potential factors that can ultimately lead to cost overrun and delay.

As it’s the last phase of any project life cycle and often ignored or less valued by even large organizations.

Slow closure can lead to dragging the final handing over of several milestones by unresolved disputes/claims linked with client’s final approval, variation order issues, acceptance of final payment certificate, issuance of retention money, issuance of performance security/bond, and failing to close out these works will cause unexpected delay and extra cost to all stakeholders of the project.

To avoid delay due to improper closure one must make sure the project is 100% completed with detailed documentation readily available. All the necessary information and documents required by all the stakeholders have been submitted to avoid doubt and conflicts in the future.


In conclusion, although time delay and cost overrun are very common in construction projects but it can be reduced or eliminated by adopting a proper performance monitoring mechanism and control system that will be integrated with all the key aspects and activities of each phase of the construction project.

Better communication among all the stakeholders of the projects with a clear understanding of the project success criteria and KPI will lead to the successful completion of the project without delay and cost overrun but by providing the best quality.

About the Author:

Vivien Goldstrong is a Consultant, Author, and Planning Manager with 22 years of experience and expertise in implementation and consultancy related to Oracle Primavera P6.