Applications and Systems Integration

In the context of IT applications and systems, the integration of information systems into new IT environments poses many challenges. One of the biggest issues in this regard is dealing with systems heterogeneity in terms of used programming languages, operating systems, and data formats. In order to ensure communication between different applications and information systems, developers must establish common interfaces. This chapter introduces middleware and Web services to facilitate applications and systems integration. Besides a brief definition and overview of middleware, the author describes several of its characteristics. Furthermore, the differences between the three middleware categories (message-oriented, transaction-oriented, and object-oriented middleware) are defined. Web services are a very popular approach for facilitating automated intra-organizational and inter-organizational communication. This chapter provides a thorough introduction to the Web service concept and the different associated standards and technologies, such as Simple Object Access Protocol (SOAP), RESTful interfaces, and GraphQL.