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Delay Analysis Methodology

A variance on the As-Built-But-For

Analysis using P6

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DisclaimerInformation contained within this presentation is for education purposesonly. How a programme or schedule is built maintained and managed isthe responsibility of the owning organisation. Focus Planning Ltdaccepted no responsibility for changes made to programmes or

schedules which are altered as a result of reading slides contained withinthis presentation. !he con"guration and settings of computer softwareare the responsibility of the license holders and Focus Planning Ltdaccept no liability for the con"guration used by the license holder.

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#hat is As $uilt $ut%ForAnalysis

As%$uilt $ut%For Analysis &for ease referred to here as A$$F' is a method of analysingthe delay on a schedule after the fact.

Long International summarise it as

The as-built but-for analysis subtracts compensable delays from the as-builtschedule for each schedule window to determine the earliest date that the contractorcould nish its work absent compensable delays. The cumulative amount ofcompensable delay calculated from all schedule windows using the as-build but-foranalysis represents the total amount of delay for which the Contractor is entitled torecover extended eld and home oce overhead costs.

(ichard ).Long Andrew A*alon (onald ).(ider! "ong #nternational $chedule and %elay &nalysis 'ethodologies +,-.

#hat A$$F loo/s to answer is 0 #hen would we ha*e "nished if the delay had not

occurred1 And #hat was the impact on the actual critical path1

A$$F loo/s at the actual critical path rather than the planned as the planned criticalpath can change on *arious occasions throughout the life of the pro2ect. #e will loo/at how to complete this analysis in Prima*era P3 this is a slight *ariation but tosoftware limitations.

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4tep - 0 !he As $uilt4chedule

!a/e a copy of the schedule &including all baselines' and open the copy in theActi*ities window. Identify the acti*ities you need to calculate delay against&/nown as the #indow'. 5nsure all acti*ities within the window are mar/edwith the Actual 4tart and Actual Finish dates. !his is the As%$uilt schedule. Addtwo milestones called 6#indow 4tart7 and 6#indow Finish7 logically lin/ asthe "rst and last acti*ities in the window and mar/ as complete. !his helps tode"ne the #indow Period.

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4tep + 0 As $uilt Logic

In the copy remo*e all acti*ity relationships from the completed acti*itiesand rebuild the logic according to the se9uence they were actually completed.!his will form the As%$uilt critical path.

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4tep 0 De%progress !he4chedule

5nsure the At ;omplete Durations match the

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4tep a 0 Identify the;ritical Path

As the As%$uilt logic was determined in 4tep + you can now remo*e theconstraints holding the acti*ities in place and re%schedule to the window startdata date. Acti*ities on the critical path should remain the same as the as%builtdates other acti*ities not on the critical path may di=er because there actualstart date will not be directly dictated by the predecessor this can becorrected using lag on the relationship but is not re9uired as we are onlyconcerned with acti*ities along the critical path. >ou now ha*e a clear As%$uiltcritical path.

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4tep 8a 0 ;ompensable Implicit

Delays

Ad2ust the At ;omplete durations on acti*ities which ha*e delay included inthem that are on the critical path. For e@ample 0 say we /now that Acti*ity includes + days worth of documented delays reduce the duration by + daysand reschedule the plan. !a/e a baseline called Implicit Delay *ariance.

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4tep 8b 0 ;ompensable 5@plicit

Delays

If the schedule contains 5@plicit Delays &dedicated delay acti*ities in theschedule' then amend the logic to ignore these acti*ities and continue on the;ritical Path. For e@ample lets say Acti*ity B was entered as 6Delay +7 thisacti*ity will be ignored and the logic amended from Acti*ity to Acti*ity -,.(eschedule to the window start data date. !a/e a baseline called 5@plicit DelayCariance.

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4tep : 0 Cariance (e*iews

ow that the As%$uilt critical path has been established and all delays recorded thenremo*ed we can re*iew what the Finish date for the window wouldha*e been had thedelays not occurred. First assign the following baselinesE

Pro2ect $aseline As $uilt $aseline from 4tep Primary $aseline Implicit Delay Cariance from 4tep 8a4econdary $aseline 5@plicit Delay Cariance from 4tep 8b

(ight clic/ the Gantt ;hart select $ars and tic/ Pro2ect Primary and 4econdary $aselinebo@es to add the bars to the Gantt ;hart. Also tic/ $aseline Milestone.

Add the following columns to the acti*ity table to gi*e you the results of the analysisEBL Project Start % !he As%$uilt 4tartBL Project Finish 0 !he As%$uilt FinishBL1 Start 0 !he planned start with implicit delays remo*ed

BL 1Finish 0 !he planned "nish with implicit delays remo*edBL2 Start 0 !he planned start with implicit and e@plicit delays remo*edBL2 Finish 0 !he planned "nish with implicit and e@plicit delays remo*edVariance BL Project Duration 0 !he *ariance between the as%build plan including alldelays and the plan e@cluding all delays a positi*e "gure indicates the number of daysthe window was delayed. !he *ariance on the last acti*ity on the critical path is theo*erall delay duration.

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4ummary

4o to summarise this *ariation on the As%$uilt $ut%For Analysis in P3pro*ides the pro2ect sta/eholders with the following informationE

!he impact of implicit delays on the window "nish!he impact of e@plicit delays on the window "nish

!he o*erall impact of all delays on the window "nish

$y comparing multiple baselines ta/en as the delay periods werecalculated we are able to see a timeline of the calculations used togenerate the claim for delays which can be issued to sta/eholders asre9uired in a single Gantt chart rather than separate pages of data.