One of the most frequently asked questions on business modelling is how many levels and what should be modelled at each level. The Zachman framework gives us some basic clues on this, suggesting that the higher levels should be conceptual and the lower levels physical detail. This is a good indicative concept and sets the scene, but no more clues to answering the original question.
I wish the answer had a simple reply.So many students of business architecture expect “painting by numbers” templates or absolute rules. It takes some level of experience of delivering architecture to realise why this is not possible. I find myself replying with the dreaded phrase ” It depends”! The reason is that levels relate to why that level exists, its motivation; simply, one size just doesn’t fit all.
Zachman gives us a clue here as on the rows the stakeholder audience sits to the left of his diagram in many depictions. https://www.zachman.com/about-the-zachman-framework
Each and every level should relate to a stakeholder alignment in that the model at the chosen level. The level should provide information on the relationships appropriate to the stakeholders needs. This is because business architecture is about communication and its artifacts respond to a demand for clarity and information. The “it depends” then relates to the reason for the model and the stakeholders involved.
The first stage in determining levels needs to be a stakeholder analysis with the communication messages clearly defined. This should give some indication of the nature of the levels and the number required, This stops wasteful modelling of either: items that don’t add to the needs of recipient which clouds the clarity of the model , or modelling of detail for modelling detail sake – i.e. stop drilling.
Further issues around modelling layer choice are about the size of the diagram and item consistency. You need levels to keep the size sensible and if having more levels allows further stakeholder segmentation of the information then that is good too.
The final issue for this post is that items have to be a the same level of importance in that grouping say ” Perform Strategy Planning” with ” Create invoice” would be ridiculous, albeit that is an extreme example, but it does illustrate the point.
So, if you have items of obviously different levels then you need extra levels. People get really hung up about levels but it is just common sense.
One bit of advice is: ” don’t model for modelling sake”.