Software Engineering

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9.1 
Embracing change
begin the next phase of development. Each review should be defined with a set of 
readiness and completion criteria. Readiness criteria establish the minimum condi-
tions that must be satisfied for the review to be conducted. During the review, many 
actions may be assigned that affect the current state of the product development 
effort. Some of these actions must be completed prior to considering the review to 
be completed. Therefore, a review may not be considered successfully completed 
until the action items have been satisfied. In most cases, this situation will cause an 
overlap of two development phases that were initially planned to be conducted in 
series.
It is important for the project schedule to be driven by progress, not by planning 
dates. Planned dates for phase initiation may not be dependent on the successful 
completion of the prior phase or review. There may be large elements of the soft-
ware architecture that are stable and can be moved into the next phase of develop-
ment while action items from the milestone reviews are resolved. The challenge is 
to understand what elements of the architecture are impacted by an action so that 
effort is not expended defining or designing elements that may be changed as a 
result of the action.
The plans for ensuing phases of development must be updated to determine the 
extent of any impact the actions have on phase-dependent work packages. It may be 
possible to minimize the impact by realigning the work packages to make best use 
of personnel resources. The objective of this replanning effort is to determine if the 
planned milestone review dates can be achieved despite change proposals or actions 
resulting from the reviews.
Phase Start Date
Phase Start Date
Completion Criteria
Completion Criteria
Planned Completion Date
Software Requirements Review (SRR)
SRR Planned Date
SRR Readiness Criteria
SRR Completion Criteria
Preliminary Design Review (PDR)
PDR Planned Date
CDR Readiness Criteria
CDR Completion Criteria
Planned Completion Date
Software Requirements Definition
Phase Start Date
Phase Start Date
Preliminary Design Review (PDR)
Software Requirements Review (SRR)
Completion Criteria
Planned
 Completion Date
SRR Planned Date
SRR Readiness Criteria
SRR Completion Criteria