Poor Cohesion 2
This flow diagram is taken from a large complex critical pricing model, used to analyse billions of dollars
It's a classic update trap, inserting a row or column anywhere will break all sorts of unexpected things. It appears to be 4 vaguely related tables, in which case it probably makes sense to put them on 4 separate sheets. Alternatively they could be stacked or otherwise aligned so any insertion or deletion would have a consistently correct effect on all blocks.
Even ignoring update issues, this is still a difficult sheet to understand. It seems (and is) an almost random collection of tables, and trying to understand the implied connections and dependencies is difficult. To understand any one block you need to understand all the others.
This sheet demonstrates poor coupling because the tables interfere with each other when they could be designed to work together in a clearer way. It also demonstrates poor cohesion because taken as a whole sheet, it just seems to be a collection of unrelated, or only loosely related tables. |
