Muddy Decomposition

gestalt - a physical, psychological, or symbolic configuration or pattern so unified as a whole that its properties cannot be derived from its parts (The American Heritage Dictionary, Second College Addition)

I've been playing with the following and would really appreciate some input. Please let me know if this is covered elsewhere.

Problem

Many real systems are difficult to decompose or reduce.

Context

After producing an initial model for a system, numerous special cases or exceptions must be incorporated to fully describe the system.

Forces

A clean decomposition of a system is easier to understand and explain.
It is often assumed there should be a simple or clear solution for all problems.
Finding a pattern that models a system may be difficult ot find or not exist.

Solution

Choose a model with few special cases.
Visually or textually partition the special cases so that the overall model is easily visible.
Possibly provide only a link to the special case (e.g. raising an exception with the exception handlers at the end of the section of code, extend relationships in use cases)

<general case>
...
if this is a special case, perform a single atomic operation
<general case>
...

Also, make sure every special case is motivated by a real and immediate need. If you think you ought to include a special case because you might need it, think instead that YouArentGonnaNeedIt.

Resulting Context

The overall model for the system is visible and necessary special cases are handled discretely.

It is unfinished--WayneCarson

It is interesting and I look forward to trying it. I put in a request that you continue so that ResultingContextNamesProblems. If it only says "problem solved", you don't need a section for it. On the other hand, if you say the next problems a person might encounter, you will do the reader a favor. -- AlistairCockburn

ResultingContextNamesProblems sounds good, but I'm not ready for this yet. I'm not even such I've (clearly) applied the solution yet. More it's a recognition of a family of problems I'm struggling with and brainstorming on solutions. --WayneCarson

One common result is that by factoring out the special cases neatly, you can find the commonality in them. Part of the value of SpikeSolution, to which this seems to me to relate, is in illuminating what isn't done. --RonJeffries

Could you expand on this finding of commonality? --WayneCarson

see perhaps also ForcesFromFailedSolutions. --AlistairCockburn