Ask Plan Academy: How To Fix P6 Partial Durations

ask Plan Academy Primavera P6 partial duration

Today we’re starting a new series on Plan Academy where will be answering your Primavera P6 and project controls questions in video rather than in text. Video is such a great medium to explore and it’s one that I want to continue to hone my skills with. So welcome to Ask Plan Academy.

Here’s a great question from Raj that we’ll be answering in the video below.

“In Construction, is it acceptable to have partial durations on my project? What do I do if I have fractional or partial durations on my project’s activities?”

Answer:
Whether a plan with partial Durations is acceptable or not is not really the right question.

Your client may or may not accept the schedule regardless. What’s important to note is that partial Durations are confusing and most often they erode the accuracy of the schedule.

First do a quick audit of your schedule, by adding 2 decimals to your Durations field and by also turning on the 12 hour Date clock in P6. Now you’ll be able to see if your Durations have any decimals or partial values.

Now you might see 2 things. You might see partial durations on the Activities, or you might see partial durations at the WBS level.

How did those fractional durations get there?

It happens in a few different ways.

First, it could be your calendar. You may have a calendar that has a lunch period or other break times in-between work periods. Make sure your calendar is created properly with no breaks in the middle of it.

Secondly, the partial durations come from the act of adding progress. When you add progress, you might not be looking at the start TIME or the finish TIME of the activity (not the date). For example, your activities might have an actual start of 10AM, instead of 8AM that adheres to the calendar times. These actual start times and actual finish times that don’t match the day’s work period will create fractional durations.

Of course, this can occur as well for a schedule that has no progress, when a constraint is added, forcing an activity to start at 10AM for example.

Lastly, lags can contribute as well. Lags can be specified in hours as well and these may contribute to partial durations in P6 too.

Do the audit, correct any problems you find with calendars, progress or lags, then reschedule to see if you’ve resolved the issues. Usually a thorough check will resolve your problems for good. Good luck!

 

If you have a question you’d like answered, post it to our Facebook page and we will queue it up for a response in this series.

Author:
Michael is an avid project controls blogger and is the Chief Learning Officer here at Plan Academy. Michael has taught 1000s professionals how to use project controls software like Primavera P6 over the past 10 years through his online courses and tutorials. Michael is a member of AACE, the Guild of Project Controls and holds his PMP certification from PMI.