In changing world of e-commerce and internet based communication, business transactions and data flows play a key role in successful business management. It is vital for companies’ information systems to implement business transactions. The purpose of this work is to propose a model for outside business process’ implementation. Basic models’ steps are: business transaction specification, data structure and architectural solution selection. Communicative action loop is proposed for modeling business processes and XML is suggested as the best method for data exchange in an internet based environment. Deploying three-tier architecture completes the models’ steps for successful business information system implementation. In this work we propose a multipurpose tool – DAO (Data Abstraction Object), based on PHP to control, manage and save XML document data. A PHP alternative way – Java Servlet technology is also discussed for using Java tools for XML processing and database connection. At the end of the work an example information system is implemented following the steps described above.