Forum Sponsor:

Viewer for .xer, xml and xls schedule files Schedule Reader™Free Trial

Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

Different Durations of WBS and the Project

5 replies [Last post]
boran ucar
User offline. Last seen 6 weeks 3 days ago. Offline
Joined: 2 Dec 2019
Posts: 2
Groups: None

7174
ek_aciklama_2019-12-04_002350.png

Hi. How can a duration of a WBS can be 50 days however upper level WBS and the project lasts 36 days at the same time?

Replies

Rafael Davila
User offline. Last seen 17 hours 3 min ago. Offline
Joined: 1 Mar 2004
Posts: 4845

I would call it WEIRD math to define duration using dates at one WBS level and sum of values within another WBS level.

  • What is the logic of this?
  • Why not inverting the calculation rules?
  • When you can have multiple calendars and the software calculations are in hours rolling-up days can yield wrong values.
  • Because the calculations for days are based on averages calculation of duration in days can be misleading. Although never as good as showing durations in hours if you have the urge to show days better show remaining workdays considering every workday duration in hours can be different.
  • Duration-Days-vs-Workdays  a single activity with a calendar where different days have different work hours.
  • Work-Days-Shifts  as you add resource calendars duration in days can get very weird, even if for a single activity.
  • Adding more activities as well as WBS phases makes it worse at the WBS levels.
  • For simple calendars and resource loading it make sense to use days as an option to enter activity duration.
Zoltan Palffy
User offline. Last seen 2 days 19 hours ago. Offline
Joined: 13 Jul 2009
Posts: 2527
Groups: None

At the Construction WBS the 36 days are working days from 12/31/2019 to 2/18/2020

At the Structural WBS the 50 days are the total of all of the workings days under that wbs

6+3+8+6+4+5+5+8+5=50

its straight math 

 

Sterling Gallagher
User offline. Last seen 1 week 2 days ago. Offline
Joined: 4 Oct 2019
Posts: 11
Groups: None

Santosh is spot on with his comment.  If you change your user preference settings to hours they should match.

Rafael Davila
User offline. Last seen 17 hours 3 min ago. Offline
Joined: 1 Mar 2004
Posts: 4845

What happens if you show all durations in hours?

Santosh Bhat
User offline. Last seen 4 hours 36 min ago. Offline
Joined: 15 Apr 2005
Posts: 240

It has to do with calendars. Where activities within a WBS group contain a mixture of calendars, the Proejct Default Calendar is used to calculate duration at the WBS Group level.

If you display your calendar column you'll see why.