REG NASA-LLIS-5163-2011 Lessons Learned - Constellation Architecture Requirements Document (CARD) Requirements v Manifest.pdf

1、Public Lessons Learned Entry: 5163 Lesson Info: Lesson Number: 5163 Submitting Organization: KSC Submitted by: Jenni Palmer Subject: Constellation Architecture Requirements Document (CARD) Requirements v. Manifest Abstract: Overly aggressive top-level requirements for launch rate may have contribute

2、d to budget overruns for the Constellation program. Early involvement of stakeholders, such as the ground operations organization, in requirements development may help prevent development of unrealistic requirements. Description of Driving Event: The CxP Architecture Requirements Document (CARD) con

3、tained the top-level tier of requirements for the Constellation program. Among the requirements in the CARD were requirements dictating the flight rate for the Constellation vehicles: three Ares V flights and nine Ares I flights within one year. A phased approach for achieving this flight rate was c

4、onsidered before the start of the CxP program. However, this approach (Spiral Development) was abandoned and a decision was made to attain this flight rate from the beginning of the program. These goals proved to be overly aggressive and led to an effort to establish an unrealistic launch capability

5、 in the near term, which may have led to budget overruns for the program. Lesson(s) Learned: The goals of the CARD were established without the proper representation from affected stakeholders, specifically the ground operations organization. Unrealistic goals can lead to budget overruns and extende

6、d schedules. Before upper-level requirements are levied by a program, the affected stakeholders should be involved in order to ensure that meeting these requirements is feasible. Recommendation(s): Involve affected stakeholders in the initial development of top-level requirements that drive program

7、architectures. Weigh the achievement of capability in the near term against the available schedule and budget. Consider taking a phased approach to reach the desired end-state capability instead of attempting to achieve the full capability up front (e.g., consider the originally proposed Spiral Deve

8、lopment approach or a Building-Block approach.) Evidence of Recurrence Control Effectiveness: N/A Documents Related to Lesson: N/A Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Mission Directorate(s): Exploration Systems Additional Key Phrase(s): M

9、issions and Systems Requirements Definition. Missions and Systems Requirements Definition.Level 0/1 Requirements Additional Info: Project: Constellation Approval Info: Approval Date: 2011-11-03 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-