Description
The time slice windows analysis represents another approach using the segmentation by project windows. However, in contrast to the As-Planned vs. As-Built Windows Analysis, this method relies entirely upon the contemporaneous schedules provided by the contractor.
The updates serve as a basis for quantifying the delays or advancements and pinpointing critical path activities. While this technique is a retrospective method (assessing delays post-occurrence), it is based on projected progress during the dates when updates were shared and mutually approved.
Time Slice Windows analysis requires an electronic version of the mutually approved baseline, consistently updated high-quality schedules, and sufficient information to be able to explain the cause of critical delays.
It is an observation-based methodology since delay events are not created or deleted, but updates are compared with each other without making any changes. Although, there is a variation of this method in which, because the updates are not good enough and there is sufficient and reliable information, the technician reconstructs the contemporary schedule to later use it in the analysis. However, this carries a risk of impartiality and is susceptible to criticism by the opposing party unless it is supported by substantial and reliable evidence.
Since contemporary schedules are used, it is considered a dynamic logic method. This dynamic approach is particularly valuable, as it accounts for evolving activity sequences. Typically, monthly intervals are adopted for update submissions, aligning with the prevalent contractual practice.
Each program shows the contemporary critical path, accommodating shifts in activity logic and potential strategies for acceleration or recovering from delays. This facilitates a focused examination of real-time project delays along the specific critical path at that moment. It’s essential that these schedules are developed with a genuine intent and not for mere commercial purposes.
Given the method’s reliance on schedules generated throughout the project’s lifecycle, specialized software has been developed to identify discrepancies between two schedules. These disparities encompass relationships, durations, and calendars, ensuring the alignment of the utilized schedule with the actual project dynamics.
Example
The following images illustrate the process to carry out the analysis with this method.
To effectively conduct delay analysis using this methodology, it is essential to follow the next steps:
- Compile and Validate Programs: Begin by identifying the programs intended for progress measurement and delay assessment. Thoroughly validate each program’s reliability and pinpoint critical activities within them. While not all updates might be directly applicable to the analysis, it’s important to consider them all for a comprehensive evaluation.
- Comparative Assessment: Systematically compare each successive update with its predecessor to discern potential influences on the critical path. This step involves confirming that completed activities accurately reflect project progress, and that planned sequences, durations, and feasibility align with realistic and achievable expectations.
- Change Identification: Identify disparities between planned and executed elements, including modifications in the critical path and alterations in activity logic and durations.
- Attribution of Responsibility: Determine the parties accountable for delays and time gains within the examined timeframe.
- Progressive Analysis: Extend this analysis across the entire project timeline, accumulating the outcomes from preceding periods to quantify the cumulative impact on the overall project.
Problems to use the planning with comercial purposes.
Time Slice analysis is a Time Segmentation Technique widely used in delay analysis expert reports. However, it’s important to recognize that Time Slice analysis demands a thorough understanding of project dynamics, sequencing, and attribution of delays or advancements. As a hybrid approach, it necessitates meticulous attention to detail and expertise in navigating its complexities to arrive at accurate and reliable delay assessments.
This approach can be defined as hybrid method because on the one hand it uses updated programs (modeling) and on the other, it compares these programs with what actually happened (observational). Updated schedules can be considered modeled as they may include prospective changes, either acceleration or delay events.
Consequently, it combines prospective and retrospective elements to comprehensively analyze delay events and critical project delays. The technique is based on the comparison between the impacted/rescheduled program and the updated program within each time interval, in order to elucidate the excusable and compensable delay periods.
However, it’s important to highlight a caveat: the application of this technique may not be advisable in scenarios where the contractor manipulates the forecast. The changes might affect durations and interdependencies among pending activities with the intention to present a more favorable project progress than reality dictates. Unfortunately, this situation is more common than it should be.
Example
Window 1
In the first window, Activity A has been completed, however instead of 10 days it has taken 15 days. In an attempt to adhere to the contractual deadline and without conducting a proper delay analysis to pinpoint accountability for the 5-day setback, the contractor decides to reduce the duration of the next activity. Consequently, the cumulative delay balance at the close of this phase is neutralized: a delay of 5 days for Activity A countered by an acceleration of 5 days for Activity B, resulting in a net delay of 0 days.
Window 2
In the second window, Activity B has been completed, however instead of 5 days it has taken 15 days. Therefore, the project has been impacted by 10 days of critical delay. To mitigate this impact and meet contractual obligations, the contractor again truncates the subsequent activity’s duration, yet without a thorough delay analysis to attribute the 10-day delay. The total delay at the end of the second window is: 10 days for Activity B and minus 8 days for Activity C, therefore, a total delay of 2 days.
Window 3
In the last window Activity C has been completed, however instead of 2 days it has taken 10 days. Therefore, the project has been impacted by 8 days of critical delay. The total delay at the end of the project is: 2 days corresponding to the second window and 8 days for the last window, therefore, a total delay of 10 days.
Due to the unjustified reductions in the duration of the activities, the critical delays of the project are 2 days due to Activity B and 8 days due to Activity C. Remarkably, despite being the sole activity completed within the stipulated baseline time, Activity C’s unjustified duration truncation has caused a critical delay of 8 days.
Conclusion
To avoid this situation, a thorough analysis of all alterations in relationships and durations becomes imperative. In doing so, it becomes evident that the 5-day delay corresponds to Activity A, while the remaining 5 days are attributable to Activity B. The extensive nature of this retroactive amendment highlights the significance of the As Built vs. As-Planned Windows analysis, in cases where updates have suffered substantial alterations.
Strengths of the Time Slice Windows Analysis
- Consideration of Realistic Replanning: This method accommodates the integration of potential rescheduling efforts, as long as they are conducted in a genuine and practical manner and not for commercial motives.
- Reliability Enhancing Information: If the updated programs are reliable, they provide a large amount of easily understandable information. In addition, the credibility of the analysis can be improved if it is shown that the actors involved used the updates for decision making and project management.
- Contemporary Critical Path Evaluation: This technique allows evaluating the delays on the contemporary critical path. However, depends on the non-manipulation of activity dates, relationships, and durations.
- Efficiency and Detail: In instances where the contemporary programs do not have to be recreated, this method is quick to execute, and a great detail can be achieved in the analysis due to the segmentation of the project.
Weaknesses of the Time Slice Windows Analysis
- Totally reliant on schedule updates, which are usually unreliable as schedules are used by contractors as a business tool and the level of quality is typically not as high as the contract schedule.
- If there are no updates, it is necessary to recreate them, making it a slow and easily criticized method, in addition to requiring expert personnel in the most common planning software.