The purpose of product departmentation is that every product is handled by separate management team and the problems faced in the development of a product are carried out by single group of employees working in that unit. The disadvantage is that the product managers need to coordinate each other for the resource sharing which becomes a difficult process because of lesser communication between the product divisions. Sometimes, products of the same company start competing with each other which results in snatching one's division profit from other division leaving behnind net profit for the company zero. However this kind of structure works best in the big organizations which have lots of products in their product portfolio.
The disadvantage of product departmentation is it needs different managerial skill for each type of product i.e very co sty for the organization