The present Water and Sanitation Knowledge System is a result of an intensive exchange and collaboration among leading specialists in the field of Water Supply and Sanitation during the 8th workshop of the Aguasan Group in Gersau in 1992.

The publication is a useful working instrument that can be employed in all phases of project, i.e. planning, evaluation, monitoring and implementation. It serves as a tool to deal with and recognize two basic questions of a project layout: who are the actors in the project, and that can the relationships between them? Who are the key actors in this network of relationships?. This book is like a snapshot of an actual project situation with a main emphasis on the structural conditions. The model serves as a thought pattern and makes possible a systematic ordering of the different interests and actors in a Water and Sanitation Project/programme, starting with a geographical comparison of the actors. It allows to observe the project/program as a whole, and permits also to look closer at specific sub-divisionmentalization of the actor. The use of this book compels a systematic procedure and calls for a clear classification.