The BCG growth-share matrix displays the various business units on a graph of the market growth rate vs. market share relative to competitors.
Resources are allocated to business units according to where they are situated on the grid as follows:
* Cash Cow - a business unit that has a large market share in a mature, slow growing industry. Cash cows require little investment and generate cash that can be used to invest in other business units.
* Star - a business unit that has a large market share in a fast growing industry. Stars may generate cash, but because the market is growing rapidly they require investment to maintain their lead. If successful, a star will become a cash cow when its industry matures.
* Question Mark (or Problem Child) - a business unit that has a small market share in a high growth market. These business units require resources to grow market share, but whether they will succeed and become stars is unknown.
* Dog - a business unit that has a small market share in a mature industry. A dog may not require substantial cash, but it ties up capital that could better be deployed elsewhere. Unless a dog has some other strategic purpose, it should be liquidated if there is little prospect for it to gain market share.
The BCG matrix provides a framework for allocating resources among different business units and allows one to compare many business units at a glance.