business logic and products
one of the examples of how business logic defines any product was visible when I started playing with flash authoring tool after long familiarity with solidworks. Flash is used by creative professionals whose thoughts has no boundaries and does not have any constraints. They are limited only by their imagination. And the tool they will use should help them by not restraining them.On the other side solidworks is used by engineers and designers who are bound by many limitations like the part they are designing – can they be manufactured by available tools and in how much cost . If they follow some standard then parts can be manufactured easily or they can be bought off the shelf also reducing cost. In this case the tool should not allow them to go out of bound and create anything they want.
Taking simple example – A Line always remains a line in solidworks or in any cad modellar. If any end point of line is fixed at any place it will always remain there unless you remove the first constrain of fixed point. And all the following operations has to be based on previous constraints. And a circle will always remain a circle.
In flash select a line and drag it . It change its shape to something else ofcourse it is bound by some equations but still slight change in selection and completely new results which suit the artist mind who most of the time is not wanting any fixed result and is experimenting for new shapes. A circle can be changed to star depending on selected point and dragging. Create two intersecting lines and they become 4 line!!