The baseline schedules are frozen in time as a reference of a plan that at one time was in accordance to contract and original plans. These got to be updated as soon as there are changes in the contract and the original or last revised baseline does not represent actual contract conditions or plans.
The updates are meant to represent actual status and plan by the Contractor and do not necessarily represent revised contract conditions, these shall be dynamic and once the Owner believes it is too far from contractual conditions might request to the Contractor to submit a recovery schedule as to represent actual contract conditions, if Contractor cannot meet actual contractual conditions the Owner might accept the schedule as an update but not as a revised baseline because acceptance of revised baseline might imply an acceptance on changed contract conditions.
The problem is many owners and contractors do not know how to deal and how to differentiate what is an update and what is a contractual baseline, these represent different things.
I agree with that we use commonly the retained logic technique. As for the out of sequence activities, can we follow progress override technique. Or if we revise the schedule at the middle of project, dont it affect the baseline schedule or will create any discrepancy with the baseline schedule.
I agree with that we use commonly the retained logic technique. As for the out of sequence activities, can we follow progress override technique. Or if we revise the schedule at the middle of project, dont it affect the baseline schedule or will create any discrepancy with the baseline schedule.
well thata a nice discussion..
expecting your comments.
thanks
Shebin
Member for
21 years 7 months
Member for21 years8 months
Submitted by Rafael Davila on Fri, 2011-06-03 14:57
Not even the experts agree on which is better, they all agree a logic revision is in order.
Some rookie schedulers believe retained logic is the magic bullet because it is the most commonly specified setting, well it is not a magic bullet. It might be that retained logic distort so much the schedule it is obvious there is an OOS event but progress override makes it easier to fix the problem.
The truth is that out-of-sequence happened and there is a chance some schedule adjustment is in order. No assumed setting assures it will hold. Still for the schedule run to be completed by the software some preliminary assumption must be selected.
After you find the OOS events/links you have to adjust schedule due to changed conditions.
OOS events are most common in SS+lag links but can happen as well in FS-zero_lag especially when using preferential logic. Like for example Start Building A before Start of Building B and during the progress of the job you find out it is more convenient to start B before A for whatever reason. It can be you can start footings of both at the same time but building A steel structure is delayed so it makes sense to start first with B. None of these settings will solve the issue correctly, the schedule will still be distorted, a change in preferential links is in order.
I will go with the specified option and will always revise logic as soon as OOS happens. After preliminary update make sure you filter for OOS events (broken links in Spider Project) and then revise logic, don't abuse PDM.
Member for
21 years 7 monthsThe baseline schedules are
The baseline schedules are frozen in time as a reference of a plan that at one time was in accordance to contract and original plans. These got to be updated as soon as there are changes in the contract and the original or last revised baseline does not represent actual contract conditions or plans.
The updates are meant to represent actual status and plan by the Contractor and do not necessarily represent revised contract conditions, these shall be dynamic and once the Owner believes it is too far from contractual conditions might request to the Contractor to submit a recovery schedule as to represent actual contract conditions, if Contractor cannot meet actual contractual conditions the Owner might accept the schedule as an update but not as a revised baseline because acceptance of revised baseline might imply an acceptance on changed contract conditions.
The problem is many owners and contractors do not know how to deal and how to differentiate what is an update and what is a contractual baseline, these represent different things.
Regards,
Rafael
Member for
14 years 6 monthshello Rafael,I agree with
hello Rafael,
I agree with that we use commonly the retained logic technique. As for the out of sequence activities, can we follow progress override technique. Or if we revise the schedule at the middle of project, dont it affect the baseline schedule or will create any discrepancy with the baseline schedule.
well thata a nice discussion..
expecting your comments.
thanks
Shebin
Member for
14 years 6 monthshello Rafael,I agree with
hello Rafael,
I agree with that we use commonly the retained logic technique. As for the out of sequence activities, can we follow progress override technique. Or if we revise the schedule at the middle of project, dont it affect the baseline schedule or will create any discrepancy with the baseline schedule.
well thata a nice discussion..
expecting your comments.
thanks
Shebin
Member for
21 years 7 monthshttp://www.cpmguru.com/assoc_
http://www.cpmguru.com/assoc_files/ENR%20-%20Critics%20of%20Todays%20CPM%20Schedules.pdf
Not even the experts agree on which is better, they all agree a logic revision is in order.
Some rookie schedulers believe retained logic is the magic bullet because it is the most commonly specified setting, well it is not a magic bullet. It might be that retained logic distort so much the schedule it is obvious there is an OOS event but progress override makes it easier to fix the problem.
The truth is that out-of-sequence happened and there is a chance some schedule adjustment is in order. No assumed setting assures it will hold. Still for the schedule run to be completed by the software some preliminary assumption must be selected.
After you find the OOS events/links you have to adjust schedule due to changed conditions.
OOS events are most common in SS+lag links but can happen as well in FS-zero_lag especially when using preferential logic. Like for example Start Building A before Start of Building B and during the progress of the job you find out it is more convenient to start B before A for whatever reason. It can be you can start footings of both at the same time but building A steel structure is delayed so it makes sense to start first with B. None of these settings will solve the issue correctly, the schedule will still be distorted, a change in preferential links is in order.
I will go with the specified option and will always revise logic as soon as OOS happens. After preliminary update make sure you filter for OOS events (broken links in Spider Project) and then revise logic, don't abuse PDM.
Regards,
Rafael