The Rational Objectory software engineering methodology is very similar to the WaterSluice software engineering methodology. The temporal ordering of the inception, elaboration, construction, and the transition phase in the Rational Objectory corresponds to the proof-of-principle, prototype, alpha, beta, and product release stages of the WaterSluice. The fundamental phases of analysis, design, implementation, and testing are the same in the two software engineering methodologies. The importance of each phase in each stage is very similar in the two software engineering methodologies. Rational Objectory does not have an explicit priority function nor a process to manage non-monotonic requirements like the WaterSluice.