Sunday, October 18, 2020

Complicated and complex

"They" say it's complicated
"They" say it's complex

Are they saying the same thing?
No, actually, there are differences:
  • It's complicated if "it" has a lot of parts and pieces
  • It's complex if the parts and pieces have a lot of interactions among them, and many of the interactions are not readily apparent, hard to model or predict, and may even lead to chaotic responses 

Good or bad; fix or ignore?

So is complicated or complex a good thing or bad? How would you know? And, what's to be done about them? 

Short answer: Chaos is almost always bad in a system, product, or process -- whatever is the project's outcome. Thus, for that reason alone, complexity may not be your friend.  

But, even without chaotic propensity, complexity is usually not a good thing: complex systems are hard to service; hard to modify; difficult to integrate with an established environment; on and on. If such are present, then complexity is present -- that's how you know.

Complicated is usually a matter of cost: lots of parts begets lots of cost, even if there is minimal complexity. Simple is usually less costly and may not necessarily sacrifice other attributes.

So, what do you do? 

You've read the theory; now, to action:

  • Chaos is bad; let's start there. The fix is to reduce complexity. To reduce complexity, a generous number of interfaces are required.
    The purpose of the interface is to block propagation of chaotic responses and contain risk to smaller elements of the system.
    Proof is in the testing. All manner of stimuli is applied to try to induce chaotic responses, and address those that occur. 

  • Complexity is first addressed by interface design; then by service design. To wit: if you have to fix something, how would you separate it from the system for diagnosis, and then how would you repair or replace? Addressing these functional problems will in turn address many of the issues of complexity

  • Complicated means a lot of parts. If that's more expensive than you want to afford, then integrated assemblies will reduce the part count and perhaps address some of the issues of complexity.
    If you've ever looked inside an old piece of electronics circa 1960 or older, you can appreciate the integrated modular design of today's electronics. Hundreds of piece parts have been integrated into a dozen or fewer assemblies.

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