Development of an accounting system - applying the incrementally modular abstraction hierarchy to a complex system

The new methodology for software development is introduced and applied to an accounting system. The new method is called the incrementally modular abstraction hierarchy (IMAH). IMAH has an abstraction hierarchy from abstract to concrete levels. Invariants defined on an abstract level are kept on a concrete level, which allows adding modules incrementally on each hierarchical level and avoiding combinatorial explosion of the serious problem in software engineering, while climbing down abstraction hierarchy in designing and modeling a complex system. This paper shows how IMAH is applied in developing an accounting system, which is fundamental in enterprise systems and a suitable example of complex software systems. At first, very simple example recording only journal vouches to a database system is used to describe methodologies of IMAH. Then, it is described how this simple system is incrementally developed to a conventional complex accounting system.