One of the problems that occurs frequently in integrated schedules during a reporting cycle is that everyone is using different data dates.

Take for example a contractor, they report to you on your week 1 with their latest schedule. This has a data date of the start of week 1. That’s great, except you closed out at the end of week 4 (just like them) so the work is always 4 weeks behind.

So what’s the problem?

Well, put simply if your programme is linked up, you’re going to impact your float paths. Take the snippet below, there’s just two schedules, one is on the 28th March and the other on the 14th March. Instantly you can see the data date line on the GANTT is at the earliest recognised data date – 14th March. But there’s a suspicious gap between A3 and B2. A3 finishes on the 21st of March. It directly drives B2. To a human brain, there’s nothing to stop B2 starting on the 22nd March, but Primavera correctly pushes B2 to the 29th of March.

B1 isn’t affected though, it still sits on the 14th March.

This is all down to how early start and finish are calculated in Primavera – and without getting into drawing Critical Path Analysis diagrams (a step to far in this short blog post) essentially in project Dev1, you have applied all the progress upto the 28th March. Therefore nothing else can start until the 29th. This Early finish is passed on (or inherited) by the next activity in the chain, regardless that it’s in another project with an earlier data date.

So you have four choices.

– Get the contractor to forward forecast by 4 weeks (Pro: all the data dates align, Con:In my experience they never review things they’ve actualised so things tend to get a bit slanted)
– Reduce your data date by a month (Pro: all the data dates align, Con: If you’re using the schedule to manage your works, you’re now in trouble)
– Get the contractor working on your systems. Advance the data date regularly (Pro: This is probably the best solution and works well, Con: Access is difficult to get right, can be overbearingly restrictive for them and they may end up double working everything)
– Ignore the problem and hope it goes away (Pro: Everyone is happy you’re not annoying them about data dates Con: All sorts of unexpected problems in critical paths as described above)

In the end, you need to weigh up the options and choose one and live with the consequences – it’s not a one fits all solution. Most probably, you’ll go for the ignore the problem issue, because it’s often not that evident to non-planners what the issue is.

The best option I’ve found is to include a snapshot of the submitted version of the contractors schedule and do a comparison between the two to see if anything is going to affect your float and do your best to mitigate that as best you can. If you can, get them to forward forecast, but in reality you’ll do as much work unpicking what didn’t happen