Every workflow gets the artifacts from the previous one, and from other sources, like the stakeholder, the experience, and general patterns. Going from conceptual database design to the logical database design requires lots of individual decisions. The designer has to decide about the grouping of objects, the quantity and quality of information, and the relations between information. He uses lots of patterns to develop the logical design. This process can be tracked with a tool, which is able to reconstruct the evolution of the logical design.
Physical model is developed out of the logical model using conversion rules.
It is the physical incarnation of logical design. The rules have to convert the technology independent logical design into target dependent physical design considering all of the constraints of the target. According to the need of the business process this rules as well as the development process can be customized on the specific needs of the implementation. Rational has implemented a full set of rules to convert from the logical design to the physical design and vice versa. It includes rules to convert classes to tables, attributes to columns, and associations to relationships, constraints, and tables.