A model should do what is required of it and no more.  Additional complexity and functionality just creates clutter that interferes with the user experience.  Design the model to do what is required using the least functionality possible.

  • Keep formulae concise 
  • Do not duplicate calculations 
  • Do not duplicate formula elements 
  • Separate complicated logic into several simpler parts 
  • Use consistent rows and 2D blocks to minimise the number of unique formulae 
  • Use as many formats and styles as necessary but no more 
  • Minimise the number of different functions used 
  • Minimise the use of range names 
  • Minimise the use of macros and carry out all calculations in Excel