From Conceptual Specification to OO Specification

Our earlier work showed how to improve the development path for an information system from initial user wishes via a conceptual specification (CS) to an implementation design in a systematic way. A CS should be implementation-independent. We generated implementations in a few directions, e.g., towards a relational DBMS using SQL. An object-oriented (OO) implementation design is another important direction.This paper works out a systematic mapping towards an OO-implementation, by giving formal mapping rules or ‘semi-automatic’ guidelines. We also look at the differences between the OO-mapping and our earlier SQL-mappings. E.g., how to specify constraints: SQL has language constructs to specify constraints, e.g., (foreign) keys, but programming languages usually lack such constructs. How to deal with it in a systematic way? This is an essential issue in software development, but one which is systematically overlooked.We start from a general analysis resulting in a CS and prove that we can create an OO-implementation out of it. Without any change in that CS, we also can create a Relational implementation.We map a CS systematically towards an OO-implementation. We use the MVC-pattern and create a default class diagram (statics/data) and default methods (dynamics/processes) from a CS. Our enhanced class diagrams inherit the constraints from the CS, which are then worked out systematically into OO pseudo-code. We generate pseudo-code which an OO-programmer can easily transform into real code. We also compare it to the SQL-mapping. Being able to map our CSs to different software paradigms shows that our CSs are truly implementation-independent