Software Process-Line Architecture and Common Processes

Extending the analogy of software architecture views and quality attributes for software process architecture, I'd like to spend some time discussing how software product lines relate to software process architecture and "common processes" across an enterprise.

Many organizations strive for standard common processes, often as part of a CMM/CMMI-based process improvement. All too often I have seen the mantra of "common process" misused and abused to make the practitioners serve the process instead of the other way around.

Processes don't create great software. People and Teams do!

And while the process needs to meet the needs of the business and the needs of the customer, it has to first and foremost serve the needs of the practitioners so that they in turn may better serve the needs of the business to deliver operational business value.

Many in management seem to have the mis-impression that "common process" means "no tailoring" and everyone does everything the same way across products and projects throughout the organization. Process variation across products and projects is regarded as something to eschewed and stamped out, beating the offenders into compliance with top-down dictates and mandates and sanctions. If everyone does everything the same way then the people are more or less "plug-and-play replaceable" and can quickly and easily be reallocated to another project or product with zero learning-curve and associated start-up costs.

This is a dangerous myth that causes irreparable harm to process improvement and common/standard process efforts. Anything that focuses on individuals and interactions as subservient to common processes and standard tools is doomed to fail, and those organizations often end-up with the processes they deserve (along with many disgruntled, frustrated workers).

The purpose of such common processes and tools is not to be a rigid restrictive straightjacket for replaceable people. The intended purpose is to recognize that such people are irreplaceable and to provide a flexible knowledge framework to guide and enable them as the help each other collaborate to learn, grow, and lead in the discovery, practical application and effective execution of practices and improvements that are the best fit for a particular product, product, community and business-environment.

The intended purpose common software processes is quite simply that of process and knowledge reuse! And as such it shares many of the same fundamental problems and solutions as that of software reuse. Indeed it could even be argued that software process reuse is but a special case of software reuse. And current prevailing industry wisdom on the subject suggests that software product-lines show the greatest promise of leveraging software reuse for greatest business value.

In software reuse, we seem to recognize that "one size does not fit all." We acknowledge that even though different products, components, and platforms may share common features, that each one may have different project parameters and environments with different quality attributes and engineering-tradeoffs that need to be "preferred" and optimized that particular application: dynamic versus static, performance versus memory, storage versus latency, throughput versus bandwidth, single versus multi processing, optimistic versus pessimistic concurrency, security versus availability, and on and on.

Software process reuse is no different. Different products and projects have their own uniquely differentiating value proposition (if not there would be no business-need to attempt them in the first place). And those differentiating aspects warrant many kinds of process variation across projects, products, technologies and teams.

Those coming from a SixSigma background may point out how SixSigma strives for reducing process variation. But it's all too easy to forget the context for that is when repeatably reproducing the same output from the same inputs for the same desired set of quality attributes and tradeoffs (not to mention the "kinds" of variation SigSigma is appropriate for trying to eliminate).

So I would advocate the translation and application of software product-line practices to software processes (software "Process-Lines" or "Process Families" if you will) and the treatment of such common processes as first class architectures that need to accommodate the views and perspectives of ALL their critical stakeholders, and which should identify their essential quality attributes and tradeoffs, approaches to managing commonality and variability, and apply appropriate patterns and tactics (such as modifiability tactics for software processes and projects) to meet those objectives.

In light of the above, Lean & Agile software development define an architectural style for such process families and their architecture. Lean and Agile principles identify some of the critical process-quality attributes for such efforts. And the corresponding enterprise and its product offerings and their market segments may identify additional quality attributes that needs to met (such as security, regulatory auditability/compliance, large-scale and/or distributed projects and teams, etc.)