Maintainability Index

Maintainability Index: Do not write functions that have a very low maintainability index. This makes the code hard to maintain.

Bad code

Any procedure / trigger that has a maintainability index < 20  

Good code

Any procedure / trigger that has a maintainability index >= 20\.
The Maintainability Index is computed as a function:
    - Lines Of Code (inverse proportional)
    - the Halstead Volume
    - Cyclomatic Complexity (inverse proportional).

More info

Bad code

Any procedure / trigger that is > 100 lines of code  

Good code

Any procedure / trigger that is <= 100 lines of code.
A full C/AL Statement counts as 1 line of code