Continuing our COVID19 scheduling series: in our previous article, COVID19 | Stop the Spread, Status your Schedule, we outlined the importance of preparing an As-Built Schedule to the date(s) when impacts due to the pandemic began, in order to gain a clear understanding of what work was complete and what remains. With this basis, the project team can turn its attention to how to complete the project in the post-pandemic environment. In this article, we will review the next step: re-baselining the project schedule with a plan to handle its inherent uncertainty.
In order to begin thinking about the future, we must first acknowledge that, like the post-COVID19 world, the post-COVID19 project will be completely different. Across the industry, the impacts to large projects will require us to re-plan and re-schedule the remaining work.
To introduce an analogy: one of the main differences between an earthquake and its aftershocks is predictability. The aftershocks can be relatively similar in strength and continue over a period of weeks, months, or even years. The COVID19 pandemic, like an earthquake, may continue to affect the economy, the workplace, and our construction projects. However, like aftershocks, future impacts can be expected and planned for. The extent and timing may not be known, but the probability of their occurrence is more likely.
Baselining a schedule at the start of a project involves making assumptions about the “normal” conditions of the project, the site, equipment, manpower, and productivity. The post-COVID19 workplace, project, and schedule must adapt and adjust to a “new normal,” wherein the baseline assumptions may not be relevant, and “aftershocks” are probable. The following are some recommended guidelines and best practices for re-baselining the project schedule.
Define New Activities
Starting with the As-Built Schedule you created, which details the remaining contract work (based on the contract requirements and scope before the impacts began), add new activities for
- Remaining Work of partially completed activities: for work that was in-progress when COVID19 impacts began on your project, consider breaking those into as-built and post-COVID activities. Due to the nature of the re-baseline, the remaining work of those activities may be impacted by potential re-work, different and varying production rates, and/or new work sequencing.
- New Work resulting from the work stoppage or delay, i.e. remobilization or rework.
For impact analysis purposes (detailed in a subsequent article), make sure to clearly identify these new activities, either in their coding, IDs, or descriptions.
Re-Study the Project
Now that we know what we need to do to complete the project, spend some time re-studying the project plan to understand how best to prosecute the remaining work and what the driving assumptions are in the “new normal”. This may include an evaluation of the following:
- Enhanced safety and health guidelines – ensuring healthy work conditions and practices may influence labor availability and productivity, office and field collaboration, stakeholder involvement, etc. Engage your safety officer, site supervisors, and foremen in planning the path forward.
- Material availability and procurement – procurement plans following the pandemic may be affected by discrete or pervasive interruptions in the supply chain; re-engage all vendors and suppliers on availability and delivery challenges in the post-COVID19 market.
- Production rates – after COVID19, production rates will likely differ from both the achieved rates before the pandemic and assumed rates in previous schedules for the remaining work. New rates will likely need to be estimated and negotiated. Contractors who were forced to furlough workers may not be able to hire back the same workers, so production may also be impacted by loss of job knowledge.
- Job logic – all job logic should be reconsidered and revised for accuracy. Re-studying the project plan provides an opportunity to re-engage the project team in construction and schedule re-engineering. The new project circumstances may provide opportunities to find more efficient paths to complete the remaining work.
- Critical Path – clearly document which activities are on the new critical path. Like fixing logic, changes to the critical path are not only possible but likely in the re-baselined schedule.
- Float – when preparing the new baseline, it’s important to build in the appropriate float and time contingency needed to cost-effectively complete the project. And, it’s important to discuss and negotiate float paths as part of a risk-based solution.
Rolling Wave Approach
If re-studying the project encounters too many uncertainties to fully re-baseline the schedule, another option would be to create a rolling-wave schedule. This type of schedule focuses on evolving the level of detail as the project progresses, with greater detail in the near-term, while allowing longer duration activities in future months or years. A common issue in scheduling is requiring the same duration and logic accuracy for work throughout a long project, at the onset or baseline. Switching to a rolling wave approach can help clarify and manage many of the risks inherent in scheduling long and/or complex projects in the post-COVID19 environment. An example of a rolling wave approach would be:
- Activities within the next 30 days can have maximum durations of 5 days.
- Activities between 30-90 days can have maximum durations of 15 days.
- Activities outside the 90-day window can have durations of 20-30 days.
Notwithstanding the potential benefit of a rolling wave approach, it remains vitally important to clearly show the critical path and the anticipated impact to project completion milestones. As part of our COVID19 scheduling series, the rolling wave approach introduced herein will be detailed in a future article as it deserves a more thorough explanation.
Use Calendars to Manage Uncertainty
In common scheduling practice, different calendars are assigned to activities to identify contract or crew working days, calendar days (for activities like concrete cure), and non-working days such as holidays and weather events. However, calendars can also help us model more complex situations. As you re-baseline in response to COVID19, consider using multiple calendars to manage production rates and time contingency, following the guidance below.
Utilizing production rates and available resources to determine activity durations in the “new normal” may become tedious and cumbersome to manage as conditions change and evolve. Moreover, as the project progresses after the pandemic, there may be additional variables affecting production rates, i.e. COVID19-related health and safety requirements, re-learning curves, etc. Some variables may affect certain activities or trades more than others. To manage these variables and to increase the flexibility of the schedule to respond to changes, we suggest using calendars to define the various productivity expectations for a working day. Here’s an example of what we mean.
Referring to the example diagram below: before the work stoppage, Crew 1 was planned to perform work in Areas 1 through 4 based on experienced production rates while working 8 hours per day, 5 days per week. After work restarts, productivity is anticipated to vary by location (or along a re-learning curve). Accordingly, we would create three new calendars (1A, 1B, 1C), based off the original (Calendar 1).
- Calendar 1: 8 hours per day, 5 days per week (100% productivity)
- Calendar 1A: 2 productive hours per day, 5 days per week (25% productivity)
- Calendar 1B: 4 productive hours per day, 5 days per week (50% productivity)
- Calendar 1C: 6 productive hours per day, 5 days per week (75% productivity)
Crew 1 continues to work 8 hours per day, but their anticipated “productive hours” per day are used to estimate revised activity durations. Using this technique adds flexibility to changing the assignment of production rate calendars in succeeding schedule updates and allows for a quick comparison between the As-Planned (pre-COVID19) and As-ReBaselined schedules, to determine the potential impact of completing the project in the post-COVID19 environment.
Time Contingency is included in the schedule as a general allowance, added to the overall project duration or to specific construction sequences, to account for abnormal conditions or random, unpredictable delays. Commonly, where weather events or seasonal conditions affect the ability to progress work, a weather calendar is used to randomly remove working days from the project calendar. Moreover, multiple levels of weather-affected calendars can be created and assigned to activities based on the operation’s sensitivity to the environment.
This concept can easily be applied to the re-baselined schedule of the post-COVID19 project. To handle the uncertainty of potential disruptions to the re-planned productivity assumptions, the project team can build COVID19-affected calendars with various levels of randomly chosen working days removed from the calendar to align with the sensitivity to COVID19-related interruptions, such as additional government stay-at-home orders or material delivery delays. Where there is more uncertainty in the near term, these calendars would have more days removed. Over the long-term, the number of days removed each month could be reduced to represent more certainty in the ability to predict monthly disruptions (or lack thereof) to the project. Here’s how this technique could be applied to the previous example of Crew 1 working different production rates.
With more uncertainty in the weeks immediately proceeding the end of the work stoppage, all calendars (1, 1A, 1B, 1C) have been modified to include potential disruptions, as follows:
- Week 1: 1 day randomly removed: Thursday
- Week 2: 1 day randomly removed: Wednesday
- Week 3: 1 day randomly removed: Tuesday
- Week 4: 0 days removed
Like the previous example, Crew 1 continues to work 8 hours per day with revised “productive hours” per day; but, in this example, random days are taken out of the calendar for potential COVID19-related disruptions. This increases the proposed time extension to account for both lower productivity and random disruptions.
Using this technique adds contingency to help manage the inherent uncertainty of the re-baselined schedule. The amount of time contingency included in the Re-Baseline should be based on a list of new and existing project risks and their potential impacts, collaboratively developed by the Owner and Contractor.
As opposed to the common alternative, where a schedule shows all time contingency at the end of the project (or buried in activity durations) and ownership of that float contentious, this technique to build time contingency into the project schedule tends to pass the scrutiny of owners and public authorities when it is collaboratively developed and assigned.
Next Steps: Recover the Schedule
Some of these solutions (like the rolling wave approach) may require contract changes to the schedule specifications. It’s important to follow what’s allowed in the contract, and to encourage the contractor and owner work together to determine the best solution for the project. The likely result of a re-baselined project schedule after a COVID19-related work stoppage is an overall delay to project completion or a significant depletion of project float. In response to requests for time extension by the Contractor, the Owner may request schedule acceleration scenarios—the topic of the next article in our COVID19 scheduling series.