Delay Analysis Methods: Examining the Impacted As-Planned Method

As part of our ongoing series on commonly utilized delay analysis methodologies, this blog will focus on another popular technique, the Impacted As-Planned method.

In this post, we will:

• Describe the method
• Walkthrough the general procedure for performing an Impacted As-Planned analysis
• Discuss things to consider when determining whether the model is appropriate for your given situation

The Starting Point: The Contractor’s Baseline Schedule

Generally speaking, performing an Impacted As-Planned analysis involves inserting a model of a known delay event or impact into the contractor’s baseline schedule.  The baseline schedule is used because it shows the initially intended performance prior to commencing the work.

Fundamental Steps of the Impacted As-Planned Method

1. Identify and quantify impacts to be evaluated
2. Select the appropriate baseline or other as-planned schedule. This schedule serves as the “un-impacted schedule” in the analysis
3. Create a fragmentary network, or fragnet, representing the impacts being evaluated by the analysis
4. Create the “impacted schedule” by inserting the fragnet into a copy of the un-impacted schedule
5. Identify the critical path of the newly created impacted schedule
6. Compare the project completion date of the un-impacted and impacted schedule to determine the delay caused by the insertion of the fragnet

The resulting schedule, after inserting the impact event, illustrates the effect of the delay/change event on the project’s completion date.

When the Impacted As-Planned Method is Appropriate

Certain considerations need to be made when deciding the proper delay analysis methodology. Every delay claim is unique and its characteristics, along with other project-specific considerations, will determine the appropriate delay analysis to implement. Key criteria, such as

• the availability of contemporaneous documentation
• requirements of the project specifications
• the quality/reliability of available schedules

will factor in to deciding which methodology is appropriate for your situation.

Simplicity as a Strength

A key strength of the method is its simplicity. The analysis is one of, if not the most straightforward methods of quantifying a delay impact. If the project and dispute are not overly complex, a more advanced method such as a Windows Analysis or Time Impact Analysis (TIA) may not be necessary. In fact, an overly complex analysis for a simple dispute may even decrease the chances of success. Less sophisticated owners and contractors may be overwhelmed by an excessively intricate analysis – especially on smaller, less complex projects.

Other scenarios where the Impacted As-Planned method can be effective:

• The Impacted As-Planned method can be useful when evaluating potential impact on the project prior to starting the work. For example, if a value engineering proposal is being discussed, it would be prudent to perform an Impacted As-Planned analysis to estimate the impact of the proposed change on the project’s completion date.  

• The Impacted As-Planned method may also be appropriate when schedules have not been properly updated or maintained during execution of the work. If the only schedule considered to be reliable is the baseline and contemporaneous documentation isn’t available to develop reliable updates retrospectively, performing an Impacted As-Planned analysis may be a viable option.

Simplicity as a Constraint

For most large and complex projects, the Impacted As-Planned method is less ideal because it does not consider the actual progression of the work. The method assumes the work proceeds precisely as indicated in the baseline schedule, which is rarely, if ever, the case. Because the method does not consider the dynamic nature of the work, it fails to recognize changes to the critical path. Assuming a multi-year megaproject perfectly adhered to the baseline plan is a difficult assumption to justify in most construction claim situations.  

In addition, implementing the Impacted As-Planned method in its most basic form does not account for concurrent delays. While certain enhancements to the method can be implemented to help combat this deficiency, the result still only provides an approximation of concurrent impacts. For situations where there are a number of known concurrent impacts, the method may not be suitable.  

Choosing the Correct Method for Your Claim

Ultimately, while it is a common delay analysis technique, the Impacted As-Planned method may or may not be suitable for your given situation.

If you have questions about the brief discussion of the method here or other delay analysis models, or to learn more about VERTEX’s Construction Claims Consulting services, call 888.298.5162 or submit an inquiry.