This paper introduces the Calculating with Concepts (CC) technique, which has been developed to improve the precision of UML class diagrams and allows the formal reasoning based on these diagrams. This paper aims at showing the industrial benefits of using such a formal and rigorous approach to reason about business processes and software applications in the early phases of the software development process. The paper discusses how the CC technique can be used in the specification of business processes and in the development of their supporting software applications or tools. This paper also illustrates the use of the technique with a realistic case study on tool integration