In our everyday lives we all consciously (or, more commonly, unconsciously) reuse knowledge. If we are experienced drivers, then we do not consciously think about how to drive. We can make a cup of tea without rediscovering how many spoons of tealeaves we should use. We write a letter without looking up where to put the recipient's address, and how to start and end the letter. In these and many more everyday situations, we reuse knowledge. It is knowledge that we have gained by studying and practicing what we have already discovered for ourselves, or more often what others have already defined. It does not occur to us to start all over and reinvent how to make a pot of tea. Instead, we reuse the knowledge that already exists and enhance it to suit our particular situation.
When specifying the requirements for a new product, you can often save a lot of effort if you start by asking, "Have these requirements or similar ones already been specified?" |