I-SPI: Improvement follows Spiral

by Brad Appleton <brad@bradapp.net>
http://www.bradapp.net/

Pattern	*Improvement follows Spiral*
Context	You need to come up with an overall battle-plan to structure the set of activities for carrying out process improvement. This may apply to improvement efforts in general (which are planned by the PIT or the PIT leader/manager), or for a specific improvement has been proposed and is now ready to be implemented by an IAT.
Problem	What framework should be used to structure the various activities of planning, implementation, assessment, and deployment for process improvement initiatives?
Forces	Group-wide process improvement efforts need to be carefully planned if they are to succeed. Numerous risks must be identified, evaluated, and approriately resolved or addressed. Omitting an important step or overlooking a key risk can result in total project failure. Too much emphasis on planning and analysis may slow progress to a virtual standstill, or prevent progress from ever taking place. Too much emphasis on action and not enough on assessment may result in sloppy and ineffective efforts that eventually fail. Even if a suitable balance of action and reflection is found, the order and frequency in which these activities are are performed can make or break a process improvement initiative.
Solution	Impose a spiral model upon the process improvement lifecycle and base it off some variant of the Shewhart cycle of Plan-Do-Check-Act (espoused by Deming and in TQM circles). Current incarnations of the spiral model include the original model proposed in [Boehm88], the "Theory W" spiral model of [Pressman] and an updated model in [Boehm96] called the Win-Win spiral model.
Resulting Context	A spiral framework for iteratively incorporating planning, assessment, and risk management activities throughout the process of implementing and deploying improvements. The spiral model is used in a manner similar to that which its proponents recommend for software development. The Shewhart cycle tailors the spiral model for use with process improvement efforts ([Grady] reaches this conclusion as well).
Related Patterns	At first glance, Improvement follows Spiral might seem somewhat contradictory to Improvement follows Process and Process follows Practice. However, it is in fact complementary to both of them. When combined with Improvement follows Process, it suggests that both the improvement process and the development process should incorporate the spiral model in an appropriate manner. The process definition lifecycle suggested by Process follows Practice fits into one of the earliest iteration cycles to perform, while the suggested process evolution outline maps very closely to most variants of the Shewhart cycle commonly employed in SPI initiatives.
Known Uses	[Grady] writes at length about Hewlett-Packard's success in using the classic Shewhart cycle together with the spiral model for planning SPI efforts. [Wiegers] describes SPI efforts at Kodak which applied a spiral cycle of Plan-Do-Assess-Verify for evolutionary improvement. [Wakulczyk] remarks upon NORAD's success applying a spiral cycle of Analyze-Plan-Do-Check-Act for SPI. [Jones,Kasunic] and [Radice] both describe success with extensions to the SEI IDEAL model, iterating the cycle of Initiate-Diagnose-Enact-Assess-Leverage in a spiral fashion for SPI planning and implementation. [SPC] and [Kellner] also recommend the use of an evolutionary spiral process model for incremental process improvement.