From our consulting experience, its possible to consider when you are better off keeping things fairly minimal with your models and when its worth employing the power of something like Business Functions.
When BF is of Real Benefit
- Large models.
- Models where time accuracy is important and might change.
- When you are going to live with a model for a long time and you need it to be maintainable and clear in its structure.
- When the users are 'power users' who could use the capabilities of BF well and understand the modelling methodology.
When you may be better off without it
- When the spreadsheet is to be deployed online. BF does not work with online spreadsheets.
- When there are issues around installing add-in software, maybe you do not want to install extra software or your company does not allow it.
- When you are going to share the model with a third party and don't think that they will want to install an extra add-in.
- When the users are not all that familiar with Excel and the additional feature set of Business Functions would be too much to take in.