Finish-to-Finish driving relationship.
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Mina:
Many of the discussion in this forum is around Critical Path Method (CPM), as it is a proven, mathematical technique for planning. These are the basics of CPM:
http://www.youtube.com/watch?v=zoBv45v_AQY
What is the difference between your "time frame" and floats as defined in CPM? Remember: lags are not the same as floats.
Maybe your question is wrong, instead of asking "after which duration from starting A1 I can start A2?", you should ask "At what point of A1 completion can I start A2?", then divide A1 in two activities: one to the point from where you can start A2, and other from that point up to A1 completion.
Still, looks like your approach to planning has been thought by someone else before, maybe you should try Liquid Planner, it looks closer to what you are trying to achieve.
http://www.liquidplanner.com/
Regards.
Hello Mina,
Why bother? After all whar you are generating is not a proper CPM logic.
I tell you what? the best approach now is to use partnership contract.
In partnership contract, the planning is so rubbish that no one is accountable: Contractor, Client, Consultant because the basic tenet of partnership contract is nobody is accountable since we are all partners, no one should be penalized.
In this situation, the best planning idiots can always fit. For a 4 years duration contract, which cost around 3 billion USD, most activities (95%) in the baseline schedule will have a total float of 1250 calendar days.
Can you imaging a 4 year contract, with budget in the area of 3 billion USD, with 95 percent of the activities having 1250 calendar days float. This particular projects will be a resting place or vacation place for highly paid (around 50,000 AED per month tax free) idiotics planners.
Im speaking based on facts.
So whatever drive your activities is irrelevant, just make money.
thank you,
Scarlett
Hi Mina
What is the difference between a duration and a time frame?
Have you seen what happens whent you update progress and the lead lag links are still hanging out?
I look forward to your method being universally adopted - my business will have to expand to keep up with all the delay claims.
Best regards
Mike Testro
Mina,
I believe you got a problem with your engineering (but who doesnt anyway?).For me, all relationships are theoretical (who said that its not?).
Are you looking for timeframe for unsure duration?
1. For Construction, I supposed it is details dependent (no problem).
2. For Engineering, It is man-hours dependent (but be careful with the coffe break, hot water burns man-hours).
3. For Procurement - This is the big problem of the engineering (P.O. first, before data sheets or any details).
cheers!
Anoon,
Let me put it in simple words, advantages of this technique are;
1- I always allow overlap between activities without facing out-of-sequence problems (I believe FS relationship is very theoretical).
2- I can lead the site team with early start for the activities instead of starting just in time.
3- I can over come the problem of inaccurate or non available data of activities (e.g. Piping erection activity should be followed by Instrumentation erection activity, if I dont have accurate data for the instrumentation BOQ I can just open a time frame with FF lag relationship and to adjust the duration so that the start of instrumentation will be after the start of piping erection with lag 7 days).
Disadvantages are;
1- Your schedule could looks in a non professional shape, as for activities which needs few days you are showing them in wide time frames.
2- During updating the schedule you must filter for the activities you decided to make them time frames and start evaluating the driving force, is it still the relation FF or the wide time frame for the activity.
3- Misuse of this method could be start scheduling without gathering real data for the activities.
Mina Arsal
Mina,
I supposed Mike doesnt have a problem with his blood pressure, but Im sure he has an allergy with FF relationship.
I dont believe you can evaluate "duration" that way, duration is only driven by resources and decisions.
cheers!
I am using Primavera 6.1
Yes it generates a critical path, the only difference it is a time frame not an accurate duration. so to keep the activity driven by relation I should evaluate the duration of A2 each update.
Hi Mina
Does your method generate a critical path?
Best regards
Mike Testro
Hi Mina,
What software are you using? I may suggest that you should also check the "driving data date or status date".
cheers!
p.s. and of course "floats" as well