Recruit a team who have the time and knowledge to work on achieving the objective. Building a Matrix Diagram can take a lot more effort than some of the other diagrams described in this book, and a longer term commitment may be required.
Decide what needs to be compared to achieve the objective. This will result in two or more lists being identified where the investigation of their relationships will help to achieve the objective.
This might also include identification of criteria to help decide what should and should not be included in the list. For example, if comparing insects with diseases, one criterion may be to exclude any insects which are unlikely to appear in the geographical area of study.