This digest summarizes the underlying structure, concepts, and ideology of the Project NEXUS manual, "A Community Approach to an Integrated Service System" (CAISS). Project NEXUS is a 3-year project charged with the development and field-testing of a technical assistance manual to aid communities in the development and/or improvement of service delivery to children with disabilities and chronic illnesses, from brith to 3 years of age, and their families. The philosophy of Project NEXUS is that a community, working together, has the responsibility and the resources to provide such services, and by doing so the entire community benefits. Section I discusses systems in the context of a family-community systems model, encompassing family, community, service delivery system, and legislation. Section II describes how to foster an alliance of service providers, parents, citizens-at-large, and advocates through the development of a CAISS committee. Section III focuses on possible actions the committee might take to deal with the community's needs. The digest is not intended for implementation purposes; persons wishing to implement the process should refer to the manual in its entirety. (JDD)