Predictable systems are systems in which correctness arguments consider both the appropriateness and the timeliness of delivered results. Such systems exhibit both statistical timing as well as bounded duration timing expectations. Such systems require suitable architectural techniques that do not preclude meeting the timing expectations. This paper provides a summary of some of these issues and the architectural concerns that surface when addressing timing constraints in performance critical systems. The currently well-known design methods are examined for their suitability to describe and record architectures with predictable performance. Relevant changes resulting in a suitable method for real-time object-oriented analysis to are suggested.