When making database design, we need to keep in mind at least the following test cases involving:

1. A single person
2. Many people (2 to 10, more than 10 should be a group action)
3. A group action (i.e. type of organisation with one or many contact people)
4. Many groups
5. Many contact people for many groups (rare)

We also need to keep in mind that:

 When we create a new case, we must either ask for client or organisation information. If it is an organisation, we should first find the default representative to make it easier to find the right person.

 There will be times where cases will be merged. No information should be altered or deleted.