Wouldn’t it be great if there were a systematic method for derivation of non functional constraints available at design time that made it possible to verify design and make implementa tion a much clearer task? This kind of methods are needed since systems of increasing com plexity has to be developed, and the cost for failing has proven to bee too high. The problem is how to derive the design time constraints into implementation time constraints, maintaining the traceability for the individual constraints, and early on get indications whether a project is about to fail or not.A method for implementation time constraint derivation has been developed and is presented in this thesis. Along with the basic method, several extensions are proposed. Evaluations of the practical usefulness of the method and the method’s scalability have been done. To prove the method’s importance in real development projects, a method for evaluation of the usability of this kind of methods has also been developed. The evaluation of the practicality shows that it is possible to find close to optimal solutions (within percent) in short time (within minutes). The evaluation of the scalability shows that the run time for finding implementable solutions scales polynomial with the size of the task graph. The evaluation of the usability shows that using the proposed method always leads to lower development cost than using an ad hoc method, in the case that the implementation is about to fail.