Translating a Primavera P6 Professional Schedule to Microsoft Project may come with a few headaches depending on the P6 feature you want to translate. Here we look at the issues involved with translating a Primavera P6 24-Hour Lag to Microsoft Project.
Translation of Primavera P6 Schedules to Microsoft Project is not recommended, but since we’ve had many requests this, here we’ll investigate translation of a simple P6 schedule that includes a 24-Hour lag.
Lag is defined waiting time between the completion of one activity and the start of another. Sometimes you want the lag day count to include weekends. This is useful for scheduling cure processes, such as concrete cure, where to curing occurs 24-7. Microsoft Project specifies 24-hour lags differently from Primavera P6. We want to be aware of this difference, and to know what adjustments to make to the translated schedule.
This article demonstrates the translation of a Primavera P6 24-hour lag to Microsoft Project, and any accompanying issues.
For a review of Primavera P6 Professional 24-hour lag definitions consult the blog Scheduling a 24-hour Elapsed Time Lag In Primavera P6.
Let’s proceed with our demonstration project, Figure 1.
Note, in particular, the lag time between pour concrete and strike forms. The bottom details lists this lag as 15-days, but counting days on the Gantt chart from pour concrete to strike forms, including weekends, shows a 5-day lag. Well, this is a 24-hour Primavera P6 lag on an 8-hour a day schedule. Because each 8-hour period is counted as one day, each 24-hour period comprises 3-days. Hence a 5-day lag, including weekends, on the Gantt chart equates to a 15-day 24-hour lag in the bottom details.
Entering a 24-hour lag in Primavera P6 is a little confusing. We generally recommend entering P6 24-hour lags in hours and letting P6 compute the equivalent number of days.
In Figure 2 we have the Microsoft Project translated file.
For a better view of the Gantt chart we add gridlines, display activity and summary task labels, and highlight the critical path in Figure 3.
An inspection of the translated schedule shows that the lag between pour concrete and strike forms is 120-hours, which is how we defined it in Primavera P6. But the Gantt chart displays 21-days, including weekends, separating pour concrete and strike forms. Not good! We need to tell Microsoft Project the concrete cure lag is 24-7.
To alter the lag definition in Microsoft Project highlight strike forms and select Task tab, Tasks ribbon group, and Information, Figure 4.
In the task information dialog, select the predecessors tab and note the lag between pour concrete and strike forms. This is the lag defined for strike forms predecessor pour concrete. In Figure 5 we see that the Primavera P6 lag was translated as a 120-hour weekday lag.
In Figure 6 we change the lag definition to make is compatible with Microsoft Project’s 24-hour lag terminology; we change ‘120h’ to ‘5ed’, which stands for five elapsed days.
Now when we display the Gantt chart, Figure 7, we count five days, including weekends, between pour concrete and strike forms.
The translation of Primavera P6 Professional schedules is not a one to one translation. In particular, Primavera P6 24-hour calendar lag is translated to Microsoft Project as a weekday’s hours only lag. It is good, however, that the Primavera P6 lag is translated in hours.
Completion of the Primavera P6 to Microsoft Project translation requires simply converting the hours to days, and specifying the lag is elapsed days using the ‘#ed’ terminology. In our demonstration example the ’15.0d’ Primavera P6 24-hour lag translates to a ‘120h’ Microsoft Project lag, which we adjust to a Project elapsed days lag, using the ‘5ed’ nomenclature.