how to automatically mark %complete of a constrained task when you reschedule its predecessor? VBA?

[CornishPlanner]

Hi Everyone, Lets see if I can explain this properly, I am a planning engineer and I am currently looking after a Scheme where we have reduced the programme (removing hidden float) and we have agreed with the client that we will track our Reduced Target date against his Contractual completion date however in order to ensure we show a critical path and to divide the "Safety" up amongst Civils, M&E and Commissioning elements (sub contractors) we need tasks between the Target completion and the Contract completion that we have called "Time Risk Allowance".

What I am trying to do is for the "buffer, or Risk Allowance" tasks to stay where they are (manual update perhaps) so we don't move or show a delay to the Client completion date however when we reschedule the programme if we are showing delay to works before the "Buffer" (Extremely likely as the scheme will complete in 2015) we want it to automatically consume the buffer by showing %complete rather than either just give a warning that the Manually scheduled task may be delayed and have to add progress manually or auto re-scheduling the incomplete buffer to start after the delayed predecessor and therefore needing a -ve lag or similar manual intervention to get the Client date back to where we want it.

I have started to investigate VBA as I think if I am to be telling project to mark a specific task with %complete it might have to be programmed rather than a Formula so I don't mind doing that but I would need guiding through it. Is there anyone who can help. Many thanks Alex

 

[JulieInMaine]

Hello Alex,

I'm not sure I understand exactly what you are trying to do - but let me see if I can restate.

You have a hard contract completion date. You anticipate you will be able to come in before that date and have an estimated "reduced target date." You'd like to add tasks between the "reduced target date' and the contract completion date?

Have you considered using Total Slack instead? The detail Gantt chart shows a bar for "free slack" you can certain change that to "Total Slack". As the time between your dates close, the bar will shorten.

Julie

 

[CornishPlanner]

Hi Julie,
Thanks for your reply. Yes that is the case however the Total Slack indicator wouldn't depict what our client wishes to see. In addition to that if there is slack in the system the critical path will as far as I am aware only show the Contractual completion date as it will be a milestone on its own constrained and if I add a lag from the predecessors the length of the "Slack" then it will push the milestone when we incur a delay to the works (which we nearly guarantee we will do).

The Client wants to see the 12w of slack divided into 3 tasks one for each discipline, 6w for Civils, 3w for M&E and 3w for commissioning (currently tasks on the critical path) and for that discipline to be allowed to consume their Buffer task as long as their works are on the critical path and we are trying to show that by marking progress on the buffer.

I will add a simple programme to illustrate what we are trying to show and that I am trying to automate when we reschedule.

The top section is how it is built now and the second section is after a reschedule, we have done work but we are also showing an increased duration so the Civils guys have used 50% of their buffer but of course I had to work out the delay, undo the delay mark that progress as % complete on the buffer then reintroduce the delay to show the correct status which is fine here but on the programme that is over 1000 lines long not so easy...

Many thanks Alex

 

[CornishPlanner]

Sorry Julie / everyone, I didn't realise you have to sign up to the 4shared to view the file, does anyone know of a free and open file sharing solution where I don't have to give my credit card details? Cheers Alex

 

[JulieInMaine]

Not to worry. I think I understand what you are trying to accomplish. Do the "buffer tasks" need to be between the anticipated end date the the contractual end date?

The problem I see is that you want the 12 weeks of buffer not to count in critical path calculation - but the contractual end date is 12 weeks out from true critical path. You can certainly set deadlines on each of the phase ends leading to the non-buffered end dates but with a constraint on the final end date you won't have the critical path your client is searching for.

So, I'm stuck with the idea of 12 weeks of "buffer" not being "buffer" but something else.

I don't know if a hammock task would work for you -- with it's start being driven by the end of the true phase and it's finish tied to the hard end date? As you get closer and closer to end date - the length of the hammock task would change. Change the bar to show duration to the right of the task and you have a quick visual of how much of a 'buffer' is left. I wouldn't worry about percent completes - thecause the buffer really isn't complete - it's just being consumed.

 

[CornishPlanner]

Thanks Julie,
The buffer tasks do need to be between the two end dates and this is the simplest way of ensuring any change in CP will ensure the buffers stay on the CP therefore I don't mind the Buffer tasks being measured on the critical path I just don't want to have to update the buffer task with progress to prevent Project rescheduling and moving the task later than we want it,(The contractual end date). Pardon my ignorance but what is a hammock task? also the 12 week has another 6 week and then another 6 week task after that so a small chain of buffer tasks that can be given to each contractor to consume before penalties are enforced to ensure that one party doesn't use everyone's agreed buffer if you see what I mean. I think we need the tasks between the end dates because without it the CP is only the last task. Cheers Alex

 

[JulieInMaine]

A hammock tasks start and finish date are determined by the start and finish of other tasks. It is essentially a copy/paste link. For details on hammock tasks see:

http://support.microsoft.com/kb/141733

I'm not sure it will work in this situation as you actually would need 3 hammock tasks with dates that are not really determined by other tasks - just the 12 weeks and two 6 week periods. So, back to your original question - it *may* be possible to update the status of a task based upon the status of another - but if you were going to do it in VBA code - you'd need a pretty clear set of criteria.

I'm going to pass the buck and suggest you post your question to a forum specific to programming in Project. See:

http://social.technet.microsoft.com/Forums/en-US/project2010custprog/threads

 

[CornishPlanner]

Thanks again Julie for your replies, and the links. I will post here if I manage to find anything

Cheers Alex

 

[JulieInMaine]

Great, thanks Alex.