During the last years we often had the opportunity to work with the renowned BCS product line of AT&T / Lucent Technologies / Avaya. Not only, that we directly supported company projects, we also complemented the knowledge of their business partners gaining vast experience on top of trained knowledge. So we decided to dedicate an entire section to the project phases of Avaya single and multisite installations. It shall aid in providing a roadmap to potential partners allowing them to identify the steps to be done. By having introduced a structured approach with interface description, partners may choose which part to keep inhouse and which to outsource