Grouping of appraisal Documents.

Hi ,

Our client has a requiremrnt to group the Appraisal documents. How best it can be done?

For example :

There are 4000 employees, requirement :

Group X contains documents which will be accessable to certain employees only like A,B,C....

Group Y contains documents which will be accessable to certain employees only like P,Q,R....

likewise...

Group N contains documents which will be accessable to certain employees only like N1,N2,N3....

Any suggestion how this can be done in best possible way.....

Thanks & regards,

Dadarao.