Wednesday, May 11, 2005

Modeling multiple business perspectives

I've been involved in a conceptual modeling exercise that, whilst moving forward, would occasionally suffer from 'modelers' block. I've been using the following standard approach to help with this.

Problem


You need to build a conceptual model of the key business entities but are finding it hard to bottom out the meaning of these entities due to conflicting viers on the entities semantics.


By modeling the business you are modeling multiple concents, e.g. scheduling, settlement and trading. Each aspect of the business views the entities from different perspectives. You need to obtain agreement on the semantics of the entities and their relationships but this is tough with everyone viewing the model from different positions.

Solution


Model the business from each useful perspective and then reconcile the models.


During the modeling workshop explicitly communicate which perspective people are to view the model from. Work through the model from that specific perspective (an no others). Narrate the place of the key entities in the business process as you go. e.g. Trader under name of a legal Entity does a deal with a counterparty at a given time for an agreed price. This keeps things practical. Once you have got as far as you can from one perspective then switch perspectives. Start with a clean sheet, as building from one model (adding perspectives as you go) forces you to reconcile models 'on the fly' - which is very hard and prone to failure. Once you have models for each perspective ready, merge them together. Where they don't match, reconcile the perspectives through a workshop.

Resulting Context


By making the perspective you are modeling from explicit you have partitioned the modeling activity into a few easier modeling problems. When you recombined the different perspectives you forced the business to reconcile the different perspectives in a controlled way. The result being a conceptual model for the business that all aspects of the organisation can buy into. In addition, the different pre-reconciliation models tell a story of how the design was developed - and are useful when explaining the model to the unitiated.

Incorrect Application


  • Using too many perspectives.

  • Switching perspectives continually in a modeling session.

  • Known Uses


  • Syntropy uses different model perspectives (rather than business perspectives) to ensure modelers know what aspect of the modeling activtiy they are address.

  • Large global organisation is currently building a conceptual model of the business and has been using this approach with a good success rate.

  • Jackson describes using problem frames to control and frame thinking processes.