Modelling is a powerful technique for creating a shared understanding of requirements. Modelling is not a dark art. Learning its techniques and best practices is a good investment not only for a business analyst, but for anyone who needs to communicate and share concepts and ideas with others.
In the next series of posts, we will review three C’s of modelling and some popular types of models.
|Three C’s of modelling: Clarity, Consistency, and Conciseness|
- Why do we start with clarity?
Here is an illustration first. How clear is the first example?
Let’s call out the problems in the first diagram:
- The diagram has no title
- It’s unclear where does the flow start
- The swimlane labels are ambiguous – in particular, it is unclear who is the actor in the third swimlane
- The lines are crossing and making the flow confusing
- Some boxes have more than one outgoing flow – without the conditions it’s unclear which flow to follow when
- The alternate flows out of the decision diamond are not labelled
- Some fonts are too small and unreadable
- It is unclear where do the labels outside of the boxes belong
- Some boxes look like comments or callouts, but it is unclear without a legend
- The descriptions of the activities in the boxes are confusing
We create models to clarify, illustrate and simplify. Each model must have the main idea that comes out clearly.
The elements of the model should be laid out in a way that contributes to clarity:
- Follow the modeling conventions and standards (in the example above – learn how to create a simple swimlane diagram or refer to the BPMN standard)
- Use accurate, clear and business-friendly labels
- Label each element, and ensure that it is absolutely clear which label belongs where
- Include a legend or a reference to explain the diagram elements
- If something happens in sequence – it should be laid out in sequence, e.g. left to right
- If the model must imply hierarchy, then arrange its elements from the top down
- Keep only the elements that are essential and add to the message
- Be clear about the boundaries of the model
- Connect only those elements that have relationships essential to the message you want to convey
- Avoid crossing the lines where possible
- Leave enough white space so that the model is not too crowded and the brain is capable of seeing the whole model. Too many elements, lines and boxes make your diagram less readable
Whenever you are in doubt whether to create a diagram, remember that a significant part of your audience will be visual.
To reach shared understanding of requirements you must explain requirements many times, many ways.
Based on the book “Business analyst: a profession and a mindset”.