In todays post I’m giving a synopsis of what the SLDC overall contributes to IS:
The structure imposed by…[the] SDLC is specifically designed to maximize the
probability of a successful software development effort. To accomplish this, the
SDLC relies on four primary concepts:
• Scope Restriction
• Progressive Enhancement
• Pre-defined Structure
• Incremental Planning
These four concepts combine to mitigate the most common risks associated with
software development efforts.
The project scope is established by the contents of high-level requirements, also
known as goals, incorporated into the project plan. These goals are subsequently
refined into requirements, then design elements, then software artifacts.
This hierarchy of goals, requirements, elements, and artifacts is documented in a
Requirements Traceability Matrix (RTM). The RTM serves as a control element
to restrict the project to the originally defined scope.
Project participants are restricted to addressing those requirements, elements, and
artifacts that are directly traceable to product goals. This prevents the substantial
occurrence of scope creep, which is the leading cause of software project faifailure.
Each stage of the SDLC takes the outputs of the previous stage as its initial inputs.
Additional information is then gathered, using methods specific to each stage. As
a result, the outputs of the previous stage are progressively enhanced with
additional information.The Software Development Life Cycle (SDLC) REF-0-02
For small to medium database applications Version 1.0d
By establishing a pattern of enhancing prior work, the project precludes the
insertion of additional requirements in later stages. New requirements are
formally set aside by the development team for later reference, rather than going
through the effort of backing the new requirements into prior stage outputs and
reconciling the impacts of the additions. As a result, the project participants
maintain a tighter focus on the original product goals, minimize the potential for
scope creep, and show a preference for deferring out-of-scope enhancements,
rather than attempting to incorporate them into the current effort.
Each stage has a pre-defined set of standard processes, such as Informal Iteration
and In-stage Assessment. The project participants quickly grow accustomed to
this repetitive pattern of effort as they progress from stage to stage. In essence,
these processes establish a common rhythm, or culture, for the project.
This pre-defined structure for each stage allows the project participants to work in a familiar environment, where they know what happened in the past, what is
happening in the present, and have accurate expectations for what is coming in the
near future. This engenders a high comfort level, which in turn generates a higher
level of cooperation between participants. Participants tend to provide needed
information or feedback in a more timely manner, and with fewer
miscommunications. This timely response pattern and level of communications
quality becomes fairly predictable, enhancing the ability of the PDR to forecast
the level of effort for future stages.
The entire intent of incremental planning is to minimize surprises, increase
accuracy, provide notification of significant deviations from plan as early in the
SDLC as possible, and coordinate project forecasts with the most current
In this SDLC, the project planning effort is restricted to gathering metrics on the
current stage, planning the next stage in detail, and restricting the planning of later
stages, also known as Out Stages, to a very high level. The project plan is updated
as each stage is completed; current costs and schedule to date are combined with
refined estimates for activities and level of effort for the next stage.
The activities and tasks of the next stage are defined only after the deliverables for
the current stage are complete and the current metrics are available. This allows
the planner to produce a highly accurate plan for the next stage. Direct experience
has shown that it is very difficult to develop more than a cursory estimate of
anticipated structure and level of effort for out stages.