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Retained Logic or Progress overide

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John Kelly
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Got int a debate yesterday with some colleagues on the topic of Progress overide or retained Logic.  when carrying out a delay analysis, Time impact for example, should the analyst use retained logic or progress overrride?


Thanks in advance


Andrew Pearce
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I believe the correct way is to initially use progress over-ride, but check that the current logic is still correct.

I know that in all of Mike T's programmes on F-S relationships are used so if the following occurs

Concrete first floor F-S Walls First to 2nd -  Planned sequence

Walls First to 2nd start prior to completion of first floor concrete Actual , and no walls to 2nd are in the area of incomplete 1st floor then progress override is correct. If some of the walls sit on the incomplete area of slab then retained logic should be used, or the relationship between 1st floor and walls changed to F-F.

Rafael Davila
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Mike Testro
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Hi John

My problem with the AACE protocol is that it is difficult to understand what is behind the garbled text.

I have considerable concerns that the new Guild document on EoT will be similarly arcane.

The starting point in any delay analysis is the original programme that was set up at the beginning of the project which demonstrates the contractor's original intention.

A delay analyst that tampers with the logic is either brave or stupid.

It is reasonable to remove or adjust obvious flaws in the programme before starting the analysis but any time over runs that result from the adjustments are to the contractor's account.

I recall getting a baseline programme that was used for a delay analysis for a sports hall where there was an acclimatisation period for the sprung floor - set as an activity - which was on the critical path.

When I changed the calendar on the task from a 40 hour week to 24/7 the eoT claim collapsed.

Best regards

Mike Testro

Rafael Davila
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from AACEI - 49R-06

Out-of-Sequence Activities Actual activity progress may override CPM calculation considerations. When actual progress occurs inactivities that should not logically begin due to incomplete preceding activities, this is termed “out-ofsequenceprogress.” The ability of CPM calculations to incorporate and consider the time implications of out-of-sequence progress on activities is essential when considering the activity’s float value. Possible methods to incorporate progress overriding logical necessity include: • Retained Logic – The data date and all logical relationships are considered and out-of-sequence work is automatically suspended until all logically preceding work is complete.• Progress Override – The data date is considered but any predecessor relationship to the out-ofsequence activity is completely ignored by the CPM calculations. Note that this does not prevent the software from displaying such relationships as if they were still was in effect.• Actual Dates – This is a hybrid of the above two methods that retains the predecessor logic if the activity has started out-of-sequence but ignores it if the out-of-sequence activity finishes.• Constraining All Early Activities – Microsoft Project optionally allows the scheduler to set a status date and then change the CPM calculation options to assign start-no-earlier-than the status date constraints to all unfinished activities that would otherwise show planned work before this date.• Ignoring the Data Date – By default Microsoft Project ignores status date considerations, thus ignoring the ramifications of out-of-sequence progress. This RP recommends against using any CPM calculations for analysis that do not take into consideration of the effects of the status date to planned work. This RP recommends the use of retained logic CPM calculation mode due to the fact that logic overridecan create orphaned predecessor activities and disregards listed constraints. If the retained logic methodproduces poor or inaccurate results, then the logic of the network should be corrected and not the CPMcalculation mode. SORRY FOR THE POOR FORMATTING BUT PP IS NOT RESPONDING CORRECTLY TO THE FORMATTING AT THE INPUT IT IS NO LONGER WHAT YOU SEE IS WHAT YOU GET