Preventive Maintenance and Install Base contract

 Hi All

I am implementing Preventive Maintenance and Service contract. KIndly find below my queries:

1. Is Install Base a must for Preventive maintenance. The reason is, my client get into business to perform scheduled maintenance for the items not sold by them. So there is no Install Base data. And there business is like this:

 

Let say there is two items L18 and M50. L18 has 5 components and M50 has 6 components. Each of these components are scheduled to be maintained. So the preventive maintenance should build service request for these 5 and 6 components. Do I need to create Install Base for L18, M50 and also for each of these 5 or 6 components. Thats hectic.