Many contracts require construction work to commence a specified number of days after the contract award or notice to proceed. The question is how best to schedule this first working day in a Primavera P6 schedule?
Construction contracts often have clauses for the commencement, prosecution, and completion of work. Sometimes, the contract manager issues a notice to proceed, a formal combined notification that:
- a master contractor has been selected
- the master contractor should begin immediately, or as of a date contained in the notice
So, the contractor must start work within a specified number of days after receiving the notice to proceed. The construction first day of work and/or kick-off meeting is this official start of the project when work begins in earnest.
The conundrum is, how to schedule the first day of work. Schedulers are often tempted to insert an activity constraint to hold the first working day in place. But activity constraints are problematic and there are better solutions.
This article demonstrates the problem with using an activity constraint to schedule the first day of work on a contract and proposes alternatives.
There are several reasons to delay the commencement of construction work. For example, the contractor may need to provide certificates of insurance or bond before accessing the construction site. The contractor may need to procure permits. The owner may limit access to the worksite to a specified window of opportunity. Regardless, in this situation work delays till a specified date.
Below in Figure 1, we have our demonstration Underground Pipe Addition Project.
We begin by defining the first working day with an activity constraint, Figure 2.
The first working day is scheduled for June 17, 2022, Figure 17. Investigating the schedule and critical activities we find that Notice to Proceed is not critical. It is not marked as critical in the critical column, and it has 5-days of total float. We therefore do not have a continuous critical path from Notice to Proceed to Project Complete.
That is a problem. A proper critical path should extend from the first activity in the schedule through project complete. The question then becomes how do we hold the First Working Day to June 17th and retain our longest path through the network?
Recently I consulted on a schedule requiring approval from the State of California Department of Transportation (CT) and they provided a solution to restrain the First Working Day to its proper date. CT recommended my client use a 7-day ‘workweek’ calendar for the Notice to Proceed start milestone and apply a 14-day lag between Notice to Proceed and First Working Day.
The 7-day calendar has no holidays, so the lag provides a straight count of calendar ‘work’ days between Notice to Proceed and First Working Day. After insertion of the proper lag, they request the removal of the activity constraint on First Working Day.
In Figure 3 we define a 7-Day calendar where every day including Saturday and Sunday is an 8-hour workday.
The 7-Day calendar is assigned to PB1000 and the Finish-to-Start (FS) relationship between Notice to Proceed and First Working Day includes a 14-day lag, Figure 4.
The purpose of assigning the 7-Day calendar to the FS relationship connecting Notice to Proceed and First Working Day is to make sure that the calendar does not include holidays and counts by calendar days. This way the number of days from contract award notice to First Working Day is easy to specify and unambiguous. And in P6 schedulers can assign each individual activity a unique calendar.
We assign the activity Notice to Proceed its own special seven-day workweek and no holidays calendar to simplify the specification of lag for Notice to Proceed leading into the First Working Day. So, CT recommends using lag to hold the First Working Day in place.
Another way to locate the First Working Day on June 17th is to extend the original duration of its predecessor activity Permits to absorb all Permits total float, Figure 5.
So, you are holding First Working Day in place with a known scope of work. And now that First Working Day is in place on the timeline, combine this effort with a June 17th activity constraint on First Working Day to track slippage in the Total Float column, Figure 6.
Then if the Permits effort slips this slippage manifests with negative total float in the Total Float column for First Working Day. This way is preferable because it is clear Permits has 10-days original duration and if it delays the cause for missing the First Working Day is apparent.
You could also tie in Review Excavation Plan and Review Mechanical Plan with FS relationships to First Working Day if they too are probable cause for a First Working Day delay.
Here we demonstrated three different ways to schedule the First Working Day of a project schedule.
Do not use activity constraints to suspend an activity on the timeline, as they cause breaks in the critical path. An agreeable way is to separate the Notice to Proceed and First Working Day with a FS and sufficient lag to align First Working Day with its contractual start date. This is the preferred approach for submissions to CT.
Someone familiar with the schedule details and the preliminary efforts preceding First Working Day may extend a predecessor proportionate to its available total float. In this way First Working Day is held in place and the continuous critical path is preserved.
The critical path is also easier to follow because the task fills up the total float and not a lag; Lag appears on the Gantt chart as a thin line that is barely visible. And if your First Working Day is properly held in place you can also reinsert the First Working Day activity constraint, and track progress from the Total Float column on the activity table.
So, using an activity constraint to hold an activity in place is problematic. But if the activity holds in place by a defined scope of work, then the activity constraint works to measure progress. Further, the First Working Day preliminary efforts are more apparent when scheduled as tasks without lags.