How many part-time job descriptions did you have to create in the project?

It uniquely depends on the project requirement.

Explanation:

There are some reason, why a company needs part-time employees.

1. If it is a "tutorial institute or Computer training institute, it needs part-time employee, based on the type of learners". Eg. College student, school student, etc.

2. The "work might be minimum" and the company would have started newly. So, they need only few full time employees and others might work in part-time.

3. Few companies may incorporate freelancers too if the amount of work that the company will receive fluctuates on a daily basis.

So based on the budget of the project, the number of resources required, the amount of work, etc, we can decide about the number of part-time users and we can design job description accordingly.