TIME IMPACT ANALYSIS TECHNIQUES

Introduction

Time Impact Analysis is one of the delay analysis methods to analyse the impact of delay events on the critical path of the project schedule. Time Impact Analysis is of cause-and-effect type and the delay impact is determined prospectively.  A baseline project schedule and an updated project schedule are required to perform a Time Impact Analysis.

Baseline Project Schedule

The detailed project schedule for a construction project is developed as per the duration of the contract with Engineering, Procurement, and construction activities. The project schedule which is agreed upon by all the stakeholders of the project shall be considered as Baseline for the project.

Updated Project Schedule

The time impact analysis requires good as-built data to update the baseline schedule.  Generally, the project schedule is periodically updated with the actual progress of activities which is an updated project schedule. 

Techniques for Time Impact Analysis

If the progress of the project is delayed by any delay event, the impact of the delay event on the project finish date shall be analysed using the Time Impact Analysis. The techniques to perform time impact analysis are as follows.

1. The baseline is to be updated on a date just before the occurrence of the delay event with the actual start date, actual finish date and % of completion for the completed activities, and activities in progress.

    

2. The critical path and the forecasted project finish date with respect to the above-mentioned updated schedule are to be noted.

    

3. If the project finish date is more than that of the same in the baseline program, the delay shall be recorded as the contractor’s delay or non-excusable delay.

    

4. The fragnets of delay events are to be inserted in the updated schedule and logically linked with appropriate activities.

    

5. The updated schedule with fragnets of delay events is to be rescheduled on the same data date to analyse the impact of the delay event on the project finish date. This schedule is called the impacted schedule.

    

6. The forecasted project finish date and critical path of the impacted schedule are noted.

    

7. If the forecasted project finish date is not more than the forecasted project finish date of the updated schedule prior to the delay event, it is considered that the delay event does not have any impact on the project finish date.

    

8. If the forecasted project finish date of the impacted program is beyond the updated project finish date and the critical path runs through the delay event and related activities, it is considered that the delay has an impact on the project finish date. The difference between the forecasted project finish dates of the impacted schedule and the updated schedule shall be considered as the impact of the delay event. Accordingly, the planned project finish date shall be revised.

    

9. This is an iterative process and is to be repeated for each delay event.

    

Illustration

In the above-mentioned illustration, the milestone shown in green colour is the project finish as per the baseline.  As a first step in Time impact analysis, the baseline schedule is updated on a data date prior to the occurrence of the delay event and the forecasted project finish date (a milestone in blue colour) is moved beyond the planned project finish date as per the baseline.  Then to analyse the impact of the delay event, the fragnet /sub-network for the delay event is inserted and linked to the appropriate activities in the schedule. The schedule with the delayed event is rescheduled.  Note that the forecasted project finished date is moved further which impacts the project finish (shown in the red colour milestone)

According to the above-mentioned illustration for time impact analysis, the difference between the impacted project finish and the updated project finish is the impact of the delay event.

Selecting the Right Construction Scheduling Software for Effective Time Impact Analysis 

An essential component in conducting an efficient Time Impact Analysis is the use of reliable construction scheduling software. The choice of software can significantly influence the accuracy and ease of updating and managing project schedules, which are crucial for Time Impact Analysis. Two of the most prominent software options in the construction industry are Primavera P6 and Microsoft Project. Each has its unique features and capabilities that cater to different project needs. In this detailed comparison article on Best Construction Scheduling Software, they delve into the specifics of these software packages, helping readers understand which might be better suited for their project’s requirements.

Primavera P6, known for its robustness and suitability for large-scale projects, offers comprehensive tools for detailed project planning, scheduling, and progress tracking, which are vital for accurate Time Impact Analysis. On the other hand, Microsoft Project, with its user-friendly interface and integration with other Microsoft tools, is a popular choice for various project sizes and complexities. Choosing the right software can streamline the process of updating the baseline and impacted schedules, making the Time Impact Analysis more efficient and accurate.

Construction Scheduling Consultants can also benefit greatly from understanding the differences between these two software options, ensuring they select the best tool for their specific project needs.

Conclusion

Time Impact Analysis is a fair method of delay analysis since the delays of all the parties are considered. Therefore, Time Impact Analysis is a preferred technique to resolve complex disputes related to the Extension of Time claims and prolongation costs.

Photo by Rodolfo Quirós: https://www.pexels.com/photo/selective-focus-photography-cement-2219024/