SA Index & Rework Calculator v2 - Copyright 2011 Lipke

8/13/2019 SA Index & Rework Calculator v2 - Copyright 2011 Lipke

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Instruction

The p-factor derived from ES provides information about schedule adherence. However, due to the inhbehavior of P, a manager cannot determine whether his/her actions have had an effect on the SA of theproject. Recall that P increases in value and concludes at the value of 1.0 at project completion, regardl

efforts by managers and workers to cause improvement. By normalizing the potential rework to remainiwork, the efforts of the project team become visible. Trending can be observed and used for project coSignificantly, the normalized value indicates the relationship of the additional work (rework) to the remaiproject work, thereby providing management impetus to make improvement.

The Schedule Adherence Index (SAI) is defined as the potential value of rework identified by the EarneSchedule (ES) p-factor (P) at status point n divided by the work remaining:

SAI = P EV f(r) / (BAC - EV)

where f(r) is the fraction of the out of sequence EV which requires rework

and f(r ) = 1 - C e^(-0.5 (1 - C))

where C = EV / BAC

By monitoring the value of SAI throughout project execution a manager can enhance his/her understanof schedule adherence (SA) performance.

The SAI indicator is interpreted as follows:

1) SAI is the amount of additional work, i.e. rework, caused by poor SA in

relation to the planned project work remaining. An SAI value in excess of

0.10 indicates a need for improvement. General areas for investigation are

lack of process discipline, poor planning, poor management, and external

schedule pressures.

2) When the SAI trend is increasing, SA is becoming worse and conversely when the trend is decreasing, SA is improving.

Computed rework values are available by performance period, cumulative to date, and the forecast byThe total forecast cost for rework attributable to lack of SA is available for comparison to both the BACFinal Cost. The total forecast is computed using an approximate integration of the SAI graph.

The worksheet, EV(r) Accrual, calculates an estimate of the out of sequence work for which accomplishis claimed. As will be observed, the value is somewhat larger than the rework forecast. Knowing thequantity, may cause management to be more aware of schedule performance discipline and the potenti

waste in the execution of the project. The calculations on this sheet are linked to the data entry and

calculations made on the SAI & Rework Calculation sheet.

Application Notes

1) To use the spreadsheet requires periodic amounts of EV(cumulative), the corresponding p-factor values, and the value for BAC.2) Enter the EV(cum), P values and BAC into the appropriate cells on the SAI calculation worksheet. Thcalculations are made within the spreadsheet and linked to the SAI Graph and Forecast Graph sheets.3) Generally, the y-axis scaling on the SAI & Forecast graph and Rework & EV(r ) Accrual graph will readjustment to obtain the best appearance.



4) To clear the SAI & Rework Calculation spreadsheet, copy #N/A into the cells having data for EV andLikewise enter #N/A into the cell for the value of BAC. Doing this causes the graphs to be cleared as w





P.ll.



Schedule Adherence Index

BAC $1,500

Status Point 1 2 3 4

EV $500 $500 $500 #N/A

P 0.580 0.680 0.870 #N/A

C 0.333 0.333 0.333 #N/A

f(r) 0.761 0.761 0.761 #N/A

EV(r) $210 $160 $65 #N/A

BAC - EV $1,000 $1,000 $1,000 #N/A

SA Index SAI 0.160 0.122 0.049 #N/A

By Period $40 $0 $0 $0

Cumulative $40 $40 $40 #N/A

Forecast $200 $162 $89 #N/A

Rework

Calculations

Measures



Rework Estimate

5 6 7 8 9 10 11 12

#N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A







$0 $0 $0 $0 $0 $0 $0 $0





13 14 15 16 17 18 19 20








$0 $0 $0 $0 $0 $0 $0 $0





21 22 23 24 25 26 27 28








$0 $0 $0 $0 $0 $0 $0 $0





29 30 31 32 33 34 35 36








$0 $0 $0 $0 $0 $0 $0 $0





37 38 39 40 41 42 43 44








$0 $0 $0 $0 $0 $0 $0 $0





45 46 47 48 49 50

#N/A #N/A #N/A #N/A #N/A #N/A







$0 $0 $0 $0 $0 $0





Status Point 1 2 3 4 5 6

Percent Complete 0.333 0.333 0.333 #N/A #N/A #N/A

SA Index 0.160 0.122 0.049 #N/A #N/A #N/A

Rework Forecast $200 $162 $89 #N/A #N/A #N/A

$0

$20,000

$40,000

$60,000

$80,000

0% 20% 40% 60

F o r e c a s t R e w o r k

Percent Complete

SA Index & Forecast R

Rework Forecast S



7 8 9 10 11 12 13 14 15

#N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A



0.00

0.01

0.02

0.03

0.04

80% 100%

S A I n d e x

work

A Index



16 17 18 19 20 21 22 23 24






25 26 27 28 29 30 31 32 33






34 35 36 37 38 39 40 41 42






43 44 45 46 47 48 49 50






EV(r) Accumulatio

BAC $1,500

Status Point 1 2 3 4

EV $500 $500 $500 #N/A

P 0.580 0.680 0.870 #N/A

C 0.333 0.333 0.333 #N/A

EV(r) $210 $160 $65 #N/A

EV(r) / EV 0.420 0.320 0.130 #N/A

By Period $105 $0 $0 $0

Accumulation $105 $105 $105 #N/A

Measures

Calculations

EV(r) Accrual



Estimate

5 6 7 8 9 10 11 12






$0 $0 $0 $0 $0 $0 $0 $0




13 14 15 16 17 18 19 20






$0 $0 $0 $0 $0 $0 $0 $0




21 22 23 24 25 26 27 28






$0 $0 $0 $0 $0 $0 $0 $0




29 30 31 32 33 34 35 36






$0 $0 $0 $0 $0 $0 $0 $0




37 38 39 40 41 42 43 44






$0 $0 $0 $0 $0 $0 $0 $0




45 46 47 48 49 50






$0 $0 $0 $0 $0 $0




Status Point 1 2 3 4 5 6

Percent Complete 0.333 0.333 0.333 #N/A #N/A #N/A

Rework Cumulative $40 $40 $40 #N/A #N/A #N/A

EV(r ) Accrual $105 $105 $105 #N/A #N/A #N/A

$0

$20,000

$40,000

$60,000

$80,000

$100,000

0% 20% 40%

C o s t

Percent Compl

Rework & EV(r) Accr

Rework Cumulative



7 8 9 10 11 12 13 14 15




60% 80% 100%

ete

al

EV(r ) Accrual



16 17 18 19 20 21 22 23 24






25 26 27 28 29 30 31 32 33






34 35 36 37 38 39 40 41 42






43 44 45 46 47 48 49 50






This example demonstrates extremely poor schedule adherence.

BAC $185

Status Point 1 2 3 4 5

EV $14 $37 $58 $82 $97

P 0.082 0.208 0.247 0.337 0.371

Trial Data

This example demonstrates a project whose schedule adherence remains fairly consistent throughout the effort

BAC $1,200


EV $240 $360 $600 $840 $1,080

P 0.200 0.500 0.700 0.820 0.870

Trial Data

This example is real data from a good performing project, demonstrating high schedule adherence.

BAC $2,488,202


EV $549,707 $668,776 $784,508 $881,288 $986,529

P 0.930 0.915 0.963 0.962 0.939

Trial Data

Measures

Measures

Measures



6 7 8 9 10 11 12 13

$113 $125 $137 $157 $177 $185

0.431 0.520 0.650 0.822 0.955 1.000

1

.

6 7 8 9 10 11 12 13

$1,200

1.000

2

6 7 8 9 10 11 12 13

$1,299,880 $1,422,033 $1,526,842 $1,617,976 $1,716,130 $1,826,991 $1,930,651 $2,015,852

0.957 0.975 0.970 0.975 0.984 0.994 0.995 0.996

3



14 15 16 17 18 19 20 21

14 15 16 17 18 19 20 21

14 15 16 17 18 19 20 21

$2,088,967

0.993



22 23 24 25 26 27 28 29

22 23 24 25 26 27 28 29

22 23 24 25 26 27 28 29



30 31 32 33 34 35 36 37

30 31 32 33 34 35 36 37

30 31 32 33 34 35 36 37



38 39 40 41 42 43 44 45

38 39 40 41 42 43 44 45

38 39 40 41 42 43 44 45



46 47 48 49 50

46 47 48 49 50

46 47 48 49 50

Documents

SA Index & Rework Calculator v2 - Copyright 2011 Lipke