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WSA QASIG TOC in 5 minutes. November 8, 2006 Jay Bakst Technologies Services Group. Contingency vs. Buffer. Parkinsons Law : Work expands to fill the time allowed Goldratt’s Principle : A project will accumulate delays, it will not accumulate gains
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WSA QASIGTOC in 5 minutes November 8, 2006 Jay Bakst Technologies Services Group
Contingency vs. Buffer Parkinsons Law:Work expands to fill the time allowed Goldratt’s Principle:A project will accumulate delays, it will not accumulate gains Moral: implicit task buffers lead to unexpected delays
Use of Buffer “Expecting early finishes to balance out late finishes is only a figment of the scheduler’s imagination” Carol Ptak, Theory H.O.W. • If task schedule more than median time: • More than half finished early • Each early task wastes project buffer • If median used: • Half tasks will be late • If optimal time used: • Most tasks will be late • Move use of buffer later in project
Results: • Explicit identification and use of Buffers lead to reduced buffer time and reduced project time Moral: Proper use of buffers gives you more time to do useful testing