The Function and Purpose of a Service
a system's behaviors signals it's real purpose
Dogmatism describes the case when our understanding of reality is viewed primarily through the lens of theory. Pragmatism has been reduced in common usage as a synonym of practical, but here we intend the tradition meaning of the adoption of observation as a first class partner to theory.
Attempting to understand the real function and purpose of a system from a requirements document or stakeholders narrative alone often leaves us blind to essential attributes. What we choose to include from the world of experience and observation to augment our understanding of what’s needed is important. Pragmatism in process modeling strikes a balance between what we said we wanted, and what we’re actually doing .
The Circumstances of Time and Place
In the end, the idea of services is just a mental model of how stuff gets done, typically modeled as a series of steps with boundaries delimited where work is handed in, and ends when the objective is realized (or abandoned). Each step is a key waypoint on the road toward some definite objective.
Being a mental model, there is no single definite solution. The “right” model of a service is one that produces value for the business under the current circumstances of time and place.
The Function and Purpose of a Service
As we model process steps with precision and detail, analyze the sources of work, the progression of events and other dimensions of the work, the very process of decomposition and analysis tend to lead us farther away from remembering the goal.
Breaking process down into components by analysis is necessary, but it has its limitations. A flow diagram is unlikely to be a faithful model of a system; it’s only a model. Reality is likely to turn out to be more subtle, open, networked and complex.
When we begin to imagine the service as a virtual machine from end-to-end, and know it well enough to set the whole thing in motion in the mind, a working functional mental model, then we are ready to think about what the aim of it all really is.
The least obvious part of the system: its function and purpose, is often the most critical determinate of the system’s behaviors.
— Majid Iqbal
System's Behaviors Signal Purpose
When we take a step back, we’re likely to discover that the whole is more than the sum of the parts. The behaviors observed when looking at the system from the outside are different from the analytical perspective. An outside vantage is necessary to understand a service’s essential purpose.
If we had all the parts of a car laid out on workbenches in a shop, we could analyze each component in detail, and study how the pieces fit together. We could work out dependencies and what the assembly sequence might be, the farther we become enmeshed in the web of dependencies, the more susceptible we are to loosing sight of the actual function and purpose of the work.
A car might be described as a system to carefully control a sequence of explosions in a confined space such that the force of the explosion can be converted mechanically into the directed motion of a large mass.
But for me, the purpose of a car is so we can go shopping or pick the kids up from school, to get to the hospital in an emergency, or to go on a once-in-a-lifetime adventure to the Grand Canyon.
The worms-eye-view of services we build through analysis is a natural result of drilling down into detail. The bird’s eye view is needed as well, so that we can see services in the context of the their actual function and purpose. A lot of our troubles come from the tension between the inside and outside view of the service. The service specification is a venue for sorting out these concerns.
In order for there to be an outside view, there needs to be some delimiter; some line marking the perimeter. The next section develops the role of establishing Service Boundaries.
Ant Rozetsky — "Steel Mill"
Let's agree to define productivity in terms of throughput. We can debate the meaning of productivity in terms of additional measurements of the business value of delivered work, but as Eliyahu Goldratt pointed out in his critique of the Balanced Scorecard, there is a virtue in simplicity. Throughput doesn’t answer all our questions about business value, but it is a sufficient metric for the context of evaluating the relationship of practices with productivity.