(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.
What does it mean when you have continous slippages in your schedule on every update? How do you solve this issue?
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Hi John,
First, a programme must be agreed with the Construction Team performing the works, in other words, they should be consulted on how they prefer to do the works, the production rates considered and resources they need.
Second, once the programme has been completed thay should buy-in and commit to the agreed programme.
Third, you need to test the logic and activity links or relationships of the programme to find out if activities are correctly link.
If you encounter continues slippage, it simply means, there is something wrong with the programme or something wrong with the performance of the team, either way, you need to investigate and find out what is causing the slippage, it may well be a bottleneck or a critical activity that needs to be addressed and resolved ASAP and it is part of the Planner's responsibility to identify and raised these issues to the Management before they even occur.
Best regards,
Daniel
I do not recall a large project with less than two schedules - contract and construction - most have more.
I would be concerned if the project is succeeding beyond expectations - since something is just as wrong as if it was failing beyond expectations. I think purpose is an important attribute over luck. Also, there are scheduling theories that make a convincing argument that an unexpectedly successful activity can cause an overall delay. For adherents of these theories, they believe that it is better to adjust the applied resources or production factor to proceed at the planned production rate.
Unfortunately here in the US and its territories it is not uncommon for schedule specifications to require all contract time to be used on the schedule, very common on Federal Government jobs. Federal Government do not understand Parkinson Law nor the purpose of probabilistic methods and buffer management. In this regard Europeans are ahead of us although things are starting to change here.
Some specifications go as far as saying that submitting an "early finish" schedule represents an automatic reduction in contract time. Also some specifications require that any changes in the schedule be submitted for approval as if "means and methods" is by the contractor only for contractual responsibility but not for scheduling.
The alternative, use a schedule for claim purposes that uses all contract time and use a tight schedule with a projected early finish that will never happen. Also use the second schedule to include plans for changed conditions you got to manage but some stupid inspector does not allows you to include in your schedule, can be a Military Sergeant that know nothing about scheduling and believes himself an expert.
This schedule shall have no contingency in it otherwise it would be useless for short term management of your daily operations. Should not even include inflated activities durations to account for bad weather, what if in the short run bad weather does not happens and you delay activities because of pessimistic projections.
I suggest avoiding intermediate buffer activities that mask short term float, let the schedule provide an unobstucted view of the optimistic you got to target in the hope of making it. I would suggest not to even use a final buffer activity, your buffer is the difference in projected activity dates versus your target, can be start or finish buffer, can be equal or different. Once again, let the schedule provide an unobstucted view of the optimistic you got to target in the hope of making it.
If this is not enough some require to use the schedule for payment purposes and this adds other inconsistencies. Take for example an activity that took you 3 weeks to essentially finish but there are payment items on dispute because of some deficiencies or repair work. The activity finished for purpose of scheduling activity successors, the activity finished for purpose of activity duration. Say it was the installation of a 1,000-hp river intake water pump but some ball bearings came defective and the manufacturer is German.
http://www.nflaace.org/index_files/john_orr_cost_loaded_schedule_updating_pdf.pdf
My workaround is to status activities as per schedule requirements to allow successors to start, when a cost issue surfaces then add a new activity to make it transparent what is going on, that the activity as intended did not happened and that there is an issue still pending. If you don't do this then out-of-sequence with retained logic option will create issues also activity duration will be distorted and this will complicate delay claims issues.
KEEP TWO SCHEDULES. One optimistic to manage your operations, to manage slippage through buffers, and one pessimistic to please the whims of others.
Be aware that optimistic schedule does not merely means shorter activity durations but planning your resources targeting the shorter durations.
Mike,
The opposite of slippage is no slippage at all, that the schedule happened exactly as planned. Slippage can go either way, positive or negative.
When using buffers it means increase or decrease in buffers, it would be silly to say buffers are fixed as if a portion is fixed and the other is variable. I believe my last statement about buffers is in some agreement with your approach you have expressed before about use of buffers, keep it simple, there is no need to create buffer activities.
I do not use buffer as activities or date difference, we simply target for early finish schedule. My preference would be to add statistical analysis to all my jobs but CPM culture at home is very poor.
Best regards,
Rafael
Hi Forest
Whats the opposite of slippage?
If the margin of error is + or - whatever then we should be equally concerned if the project is succeeding beyond expectations.
Best regards
Mike Testro
I agree with Rafael - from my experience, on building projets schedules are considered locked at notice to proceed and slippage requires negotiations, on heavy civil projets slippage is life
also, I do not think there is an underlying theory of construction production that allows calculating task durations with greater accuracy than +/- an unknown amount - the current theories are that loose, so if there was not slippage I'd suspect someone is covering up the slippage or it is just luck
John,
Need some more info before I can give you much of answer:
1) Are the slippages vs a static baseline, or vs the planned progress at last update?
2) Are these slippages occuring across all disciplines / departments / work fronts / work gangs, or is there a pattern?
3) Have the people responsible for the work been involved in agreeing the dates / sequence / durations?
4) Have the people responsible for doing the work given you any reasons why they are slipping? What are these reasons?
5) Has there been (m)any changes to scope or specification?
6) Do the activities in your critical path change at each update, or is it the same path, just running later?
7) Is the programme well-built? (i.e. no dangles, minimal use of constraints and lags, mainly FS relationships, etc)
8) Is the programme resource-levelled?
Cheers,
G
Plans never go as planned, you got to manage your schedules with this in mind. Manage your jobs targeting for tight schedules.
http://www.spiderproject.com/images/img/pdf/Project%20Control%20Methodologies.pdf
Email: PPadmin@planningplanet.com
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