Production planning would typically be as you could infer from the name, planning the future demand requirements for products so that you know how much you need to produce, when and the compare real production requirements with the ones initially planned.
Need the base required dimensions at least Category, Account, Time and Entity. In you case account does not necessarily have to be Accounting "accounts" but could also represent the planning concepts as Volume, Rebates, Prices, Cost, Sales, Demand, etc. Your entities could be Mfg plants, Cost Centers. Additionally depending on your business requirements you could also need other User-Defined dimensions such as Product, Raw Material, Customer, etc.