Facilitating Software Architecture

Chapter 14. Variability and the Interconnectedness of Decisions

People who practice architecture are confronted with decision after decision. These decisions come in all shapes and sizes, and in a sociotechnical system, decisions are affected not only by technical challenges but also by sociological ones.

When deciding, the challenges go beyond knowing which option suits you best right now. You also need to know how your decision will affect other decisions and if there are other decisions that affect yours. Other people’s decisions can affect your confidence in deciding or sometimes lead to an out-of-control feeling if the decision is in someone else’s hands.

In this chapter, I’ll examine four ways that decisions can be interrelated. And I’ll introduce you to a tool for understanding the relationships that connect decisions, boosting your decision pathfinding skills and helping you navigate through the tangled sociotechnical jungle.

Finding a Path Through Variability

We don’t decide in a vacuum. Decisions are inevitably interconnected. Not only that, but the act of deciding is frequently hindered by emotion and ego. Interconnectedness and emotionality add variability. Unfortunately, variability arising from these two sources is usually the most expensive kind.

Expensive technical variability arises from not knowing which option will yield the best outcome given your context—or even if it will work at all—until you take it all the way to production.

Expensive sociological