http://www.contextures.com/xlDataVal03.html

The above link might be what you are looking for.

"Linda" wrote:

I need to allocate people to jobs available hence making rotas for the year.
I have a list of names sheet and 2 sheets with different types of jobs, some
being for 4 months and some 6 months (they all start at the same time which
helps)
I have started by putting all the possible start dates across the top of all
sheets and blanking out dates not applicable (ie depending if 4m or 6m job)

I need to: allocate jobs to each name for the year (not randomly), also put
the name on the job sheets. Can anyone let me know if there is an easy way
of cross-referencing all info so I don't double book people or jobs or omit
anyone or job? I was thinking of ways to flag this up? Hope you can
understand! Thanks