The building of a working relationship does not wait until there is some magic kickoff meeting. You want to begin to use the template and start building detailed tasks with the person(s) who are designated as project leaders for the vendor. Start identifying some issues as well. Then you can discuss how the issues are to be resolved. A basic guideline is:

You want to define and agree on the issue resolution method before significant issues arise.

If you wait until an issue appears, then everyone will have to cope with solving the issue at the same time that they are working on how to resolve issues in general—too much to ask at one time.

You should do joint planning with them to define detailed tasks in the template for their work. By doing this with your employees and those of the vendor, you start to build working relationships that will be very important later. Another guideline is:

You need to create patterns of working relationships and behavior at the start of the vendor’s work.

This has several benefits. First, you see how the vendor thinks and what techniques that they use. Second, your employees will start having detailed technical contacts with the vendor’s employees.

Get some detailed tasks going right away. This shows the vendor that you are serious. If there is a big time gap between when the contract is negotiated and when work begins, the vendor may not think that you are serious and may reassign their staff to other clients. By starting work early you avoid this situation.