This paper discusses some experiences from a project developing an object-oriented framework for a family of fire alarm system products. TeleLarm AB, a Swedish security company, initiated the project. One application has so far been generated from the framework with successful results. The released application has shown zero defects and has proved to be highly flexible. Fire alarm systems have a long lifetime and have high reliability and flexibility requirements. The most important observations presented in this paper are that the programming language C++ can be used successfully for small embedded systems; and that object-orientation and framework techniques offer flexibility and reusability in such systems. It has also been noted that design for verifiability and testability is very important, affecting as it does both maintainability and reliability.