Nowadays, businesses need a system that can provide flexibility, reusability and simplicity for their business solutions. However, if business logics or rules are implemented using procedural paradigms, then the business systems will become more complex. In this paper we treat business logics separate from system logics, whereby we analyse a business by describing its rules and developing a set of rule statements. These business rules will be treated as a separate component in the design and implementation of the system. We have found that our proposed method leads to a system, which is more customisable, flexible, efficient, and reusable, in terms of business rules. In the paper, we also present an example of online quotation and order placement system developed for manufacturing company based on our proposed method which has been implemented using XML technologies. This example illustrates how to construct reusable business rules during development of a business solution based on software engineering principles.