One of the findings from my Master’s Research Project was this framework for planning a systems-modelling project with a good balance between the scope to be covered, and the time and other capacities available from the modelling team:
The scope and size of a model depends upon the amount and types of knowledge and complexity it needs to represent. I’ve identified six dimensions of scope for system models of cause-and-effect, but this framework could also apply to other types of models.
Modelling a larger scope requires more capacity for expertise, modelling, research and facilitation, which all lead to higher-quality model content. The modeller’s skill and software determine the model’s format and clarity, which influences comprehension, to counteract the difficulty of understanding a larger model. The scope and requirements for a model are likely to evolve as the subject becomes better-understood.
A modeller can read and synthesize source documents, but to get full benefit from the model, subject-matter experts need to devote considerable time to a modelling project. Discussion can shape the scope and expression of a model while building collective knowledge, a sense of ownership, and commitment (buy-in) to the results. Gaps in knowledge may be filled by primary or secondary research; integrating these multiple sources increases the reliability of modelled information. Spending time to discuss ideas, with people with lived experience and other perspectives, will yield more valid results.
To be useful, a model needs to have a scope that fits its purpose, be easy to understand, and be of sufficient quality. Expert and facilitator time is also needed for using the model, to get high-quality results such as decisions about a complex system.
You can read more of my recommendations for balancing scope and capacity, beginning in section 7.6.5 of my research project report. This framework emerged from developing a very large system model and using it, under tight time constraints, to prioritize options. It helps me stay realistic while planning consulting projects. Let me know if you also find it helpful!