EC25-Schedule_Estimation

Development step4 design4 document 2 finish code 4

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Unformatted text preview: ent step3 Document, 2 Finish Code, 4 Product test, 4 8 PERT chart development step4 Design,4 Document, 2 Finish Code, 4 Test data,2 Product test, 4 Test drivers, 6 9 PERT chart development steps 5, 3, 4, 5, 3, 4, 5 Design,4 Requireme nts,3 Document, 2 Finish Code, 4 Test data,2 Product test, 4 Test plan,2 Test drivers, 6 10 Critical Path Procedure 1. Label the Start node (0, 0) 2. For all unlabeled nodes N whose predecessors are all labeled nodes, compute the earliest possible start time as the latest finishing time of all its predecessor S N = max [ Fi ] nodes i∈P ( N ) where P(N) is the set of predecessor nodes of N Compute the corresponding finish time FN=SN+DN ,where DN is the duration of activity N, Label the node N as (SN, FN) 3. Repeat Step 2 until no unlabeled nodes remain. 11 Critical path determination after two iterations (3, 7) (0, 3) (0, 0) Requireme nts,3 Start Design,4 Document, 2 (3, 5) Finish Code, 4 Test data,2 Product test, 4 (0, 2) Test plan,2 (2, 8) Test drivers, 6 12 Critical path determination after five iterations (7, 9) (3, 7) (0, 3) Design,4 (7, 11) (0, 0) Requireme nts,3 (3, 7) (3, 5) Document, 2 Code, 4 (13, 15) (11, 15) (7, 11) Start (0, 0) (0, 3) Test data,2 (0, 2) Test plan,2 (3, 5) Product test, 4 (9, 11) (11, 15) (2, 8) Test drivers, 6 (5, 11) 13 (15, 15) Finish (15, 15) Latest-Start Procedure 1. Underlabel the Finish node F with its start and finish times as determined from the critical-path procedure, that is (S’F, F’F) = ( SF, FF) 2. For all non-underlabeled nodes N whose successors are all underlabeled nodes, compute the latest possible finish time as the earliest starting time = min [ S 'i ] F ' N of all its successor nodes. i∈S ( N ) where S(N) is the set of successor nodes of N. Compute the corresponding latest-start time S’N =F’N - DN where DN is the duration of activity N, Underlabel the node as (S’N, F’N) ,Compute the slack time for the activity as LN =S’N - SN (or LN =F’N - FN) 3. Repeat Step 2 until no non-underlabeled nodes remain. 14 Shortening the Critical Path (6, 8) (3, 6) (0, 3) Design,3 (6, 8) (0, 0) Requireme nts,3 Start (3, 5) Document, 2 Finish Code, 2 (8, 12) Test data,2 Product test, 4 (0, 2) Test plan,2 (12, 12) (2, 8) Test drivers, 6 15 • Cost-Schedule Tradespace Generally, reducing schedule adds cost Analysis * 2 people = Pair programming: 60% schedule – 120% cost • Increasing schedule may or may not add cost – – • Can often decrease both cost and s...
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This document was uploaded on 03/10/2014.

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