Start with the doors, not the keys
A good key system begins with a door list: front entry, office, storage, restroom, back door, mechanical room, tenant space, or restricted area. From there, access can be matched to roles instead of copying keys as problems come up.
When to reset key control
Employee turnover, tenant changes, lost keys, copied keys, and manager changes are common reasons to rekey and reorganize access. If nobody knows which key opens what, the system is already costing time.