Rapid Application Development / Advanced Excel Development

Modular blocks

A 'block' is a area of cells surrounded by empty cells, that performs some analysis

Spreadsheet architecture is not very hierarchical, unlike much of the data they are used to analyse. A single cell could be considered the smallest unit of execution. These can (and should where appropriate) be grouped into logical blocks. A block should generally have similar data types, or similar formulas. Colour can be used to differentiate, as can a blank row and column. Empty cell borders are preferred because they allow use of current area and current region features.

It should be possible to understand a single block without reference to others, and ideally the formulas will be similar enough to make copy and pasting simple and reliable. Having inconsistent formulas scattered within a block creates a real risk of inadvertent overwriting. The quickest and easiest way to check all formulas in a block are consistent is to copy one cell/row/column over the others - that will cause problems if certain cells have a special inconsistent formula. Future maintainers are likely to do this, so plan ahead and use similar formulas where possible - and big highlights for special cases.