An object-oriented framework for transaction capture using co-operating business rule components

In a dealing-room system at a London bank, the transaction capture programs had been built using a GUI-based prototyping approach. This had led to programs with superficial similarity but inconsistency of internal structure which made maintenance difficult. To re-engineer the programs a control framework was devised separating the GUI interface (presentation layer), business rules and persistent storage. The framework allows business rules to be developed as independent, co-operating components. This makes it easier to develop and add new function or re-use previously-developed function. Business rule components are developed and tested separately, then used as building blocks for development of more complex components. They are re-usable because the same business constraints and calculations apply to many different transaction types.