
The question of “how big should my model be” is an evergreen Model-Based Design question. Too small and time is wasted on build, test and review tasks. Too large and the model is difficult to debug and maintain. The recommended size has always been a range with one critical factor: the ease of communicating information from one person to another. But in the COVID remote working environment, has the sweet spot shifted and if so, what can Model-Based Design do to address this?
Going down the rabbit hole

The English idiom “going down the rabbit hole” is a reference to Lewis Carroll’s ‘Alice in Wonderland’ and refers to any pursuit where action is taken but the outcomes are ‘never ending and nonsensical’. Remote work can easily lead people down rabbit holes due to a lack of communication. In the office, sitting next to Sid & Beatrice, Marie & Pierre I have opportunities for regular, small sanity checks. How can we foster that same culture from behind a webcam?
Bring down the wall

When working remotely there are 2 keys to effective Model-Based Design reviews
- Select the focus of your review: Are you performing an architectural review or a functional review?
- Architectural: provide the I.C.D. and the execution flow of the atomic units
- Functional: Provide the simulation results and the requirement documentation
- Leverage integration models: Here is the MBD Key, the use of shell (child) and integration models gives you a natural decomposition between the architectural review (integration models) and the functional reviews (shell/child)
How this keeps you whole

Rabbit holes are best avoided through timely reviews. By leveraging the Integration / Shell concepts, a natural break point in the review process exists.
Shell models map to between 2 ~ 4 high level requirements. When you have completed the work on any of the requirements, call for a review.
Integration models map onto system level requirements. When any of these change, call for a review.
Reflecting back to the start

In the same spirit of avoiding rabbit holes, we want to prevent the mirror problem of too many reviews. Unless the review is part of an Agile Stand up, 45 minutes to an hour is an appropriate amount of time. If reviews are routinely taking less then 30 minutes, reconsider the tempo of the meetings. While time spent in reviews is important if you spend too much time in them you end up with the Red Queen’s Dilemma.