1、 Public Lessons Learned Entry: 4770 Lesson Info: Lesson Number: 4770 Submitting Organization: JPL Submitted by: David Oberhettinger Subject: Recurring Flight Project Problems Evince “Common Threads“ Abstract: A Common Threads Workshop was held by JPL in 1996 and 1997 as a venue for seasoned flight p
2、roject managers to convey knowledge of recurring problems or situations that dominate the project life cycle to future project leaders. Most of these issues appear relevant today. The workshop summary reports suggest “corrective strategies“ for coping with “common thread“ issues that arise on projec
3、t after project. Description of Driving Event: JPL held a Common Threads Workshop in May 1996 and again in July 1997 as a venue for seasoned flight project managers (PMs) to convey some key knowledge to the next generation of PMs. The premise in organizing the workshops was that “common threads“ exi
4、st that are evident in project after project, in the form of similar flight and test failures or failure mechanisms, programmatic issues, and sometimes serious oversights. These problems are well understood and often solved in some innovative way on one project or program, but the knowledge is frequ
5、ently not passed to another project with a similar problem. Thirteen years after the publication of the workshop reports (References (1) and (2), most of these overriding engineering issues still appear relevant. The workshop presentations consisted of experienced PMs and other JPL engineering leade
6、rs describing issues and coping techniques that arose during their program/project stewardship that gave them a deeper understanding of constraints to mission success. The format of each presentation was either “war stories“ specific to a project or “lessons learned“ from general experience. The 199
7、6 workshop involved mostly PMs focusing on programmatic issues, while the 1997 workshop involved more Engineering and Science Directorate personnel focusing on design issues. The common threads mutual to both workshops fell into the following 8 general categories: Communications issues at all levels
8、 Hardware interfaces Contractual interfaces Heritage and commercial-off-the-shelf (COTS) issues Parts issues Programmatic issues Assembly, Test, and Launch Operations (ATLO) and launch site issues Product assurance issues Within these groupings, there was a high level of agreement between presenters
9、 on specific common threads, such as: “Failure to convey lessons learned from one project to the next and to all project elements, including the contractor and subcontractors“ (a “Communications“ common thread). “Placing too much trust in inherited hardware“ (a “Heritage/COTS“ common thread). “Deter
10、mining the proper amount of burn-in time“ (a “Parts“ common thread). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-“Growth in science requirements that jeopardize the mission“ (a “Programmatic“ common thread). “Failure to consider the differences i
11、n the test environment and the flight environment“ (an “ATLO“ common thread, often stated as “Test as you fly“). References: 1. Arthur F. Brown and John E. Koch, “JPL Common Threads Workshop Summary Report,“ JPL Document No. D-13776, May 31, 1996. 2. Arthur F. Brown and John E. Koch, “JPL Common Thr
12、eads Workshop II Summary Report,“ JPL Document No. D-14906, July 25, 1997. Lesson(s) Learned: There exist overriding “common thread“ engineering issues that are evident in flight project after flight project, but techniques for coping with recurring constraints to mission success are not always comm
13、unicated to the next generation of PMs. Most of these common threads may not be unique to JPL, but they are all significant to JPL because they are central to its engineering culture. Recommendation(s): Each summary report provides “corrective strategies“ for coping with specific common thread issue
14、s. (There is a 1990s-era emphasis on coping with “Faster-Better-Cheaper“ constraints, particularly in Reference (2), but many of these constraints apply to todays cost-constrained missions.) In addition, the reports provide a set of overall recommendations specific to the general categories of commo
15、n threads: 1. Communications. Work on communications at all levels - i.e., within the project; between the project and such support organizations as product assurance and safety; as well as with the contractor, subcontractor, and fabrication and assembly personnel. Projects must take advantage of le
16、ssons learned and other knowledge that already exists at the Laboratory, though it may require crossing an organizational boundary. 2. Interfaces. Beware of interfaces of all kinds - hardware to hardware; hardware to test and ground support equipment (GSE); spacecraft to launch vehicle; and people t
17、o people. Be especially careful when a system is designed by one group and used by another. 3. Heritage. Evaluate inherited hardware as thoroughly as new hardware. There is a tendency to put too much trust in inherited hardware. Several examples were presented in which the new spacecraft application
18、 presented life or environmental challenges not faced in the original application, and the inherited device failed. 4. Parts. Semiconductor parts are getting more reliable, but NASA and DoD programs have less control than they once did. It is becoming harder to get radiation-hardened parts, and this
19、 presents new challenges such as providing Single Event Effect (SEE) tolerance at the system level. Work with the Parts organization early to prevent delays on long lead items. 5. Programmatic. There is “sales“ pressure for projects to provide extraordinary levels of science and mission complexity w
20、hile staying within severely constrained schedules and budgets, and upper management must be made fully aware of any increased risk. Monitor the fundamental program assumptions, and replan when fundamental assumptions change. Ensure that project reviews are thorough: the major benefit of design revi
21、ews is the time spent preparing for them. 6. ATLO and Launch Site Issues. The workshop consensus on the correct amount of time in ATLO was somewhere between twelve and eighteen months, depending on how well people, parts and processes are understood. The new projects wish ATLO (i.e., Integration & T
22、est) to be flexible enough to add new tests as the knowledge of the hardware increases. Provide time and budget contingencies in ATLO to deal with the unexpected. Ensure that written, well rehearsed, procedures are available before shipping hardware to the Cape. 7. Product Assurance. There is a stro
23、ng relationship between adequate product assurance and successful programs. The PMs favored continuation of the practice of having Mission Assurance (especially Reliability Engineering) personnel collocated with Provided by IHSNot for ResaleNo reproduction or networking permitted without license fro
24、m IHS-,-,-flight project personnel. Evidence of Recurrence Control Effectiveness: There are documented flight project practices that emphasize infusion of lessons learned. However, the theme of this document is that these “common thread“ issues will recur. Documents Related to Lesson: JPL Common Thr
25、eads Workshop Summary Report, 31 May 1996 Click here to download communication document. Mission Directorate(s): Space Operations Science Exploration Systems Aeronautics Research Additional Key Phrase(s): Program Management.Science integration Program Management.Program planning, development, and ma
26、nagement Program Management.Contractor relationships Program Management.Configuration and data management Program Management.Communications between different offices and contractor personnel Missions and Systems Requirements Definition. Missions and Systems Requirements Definition.Configuration cont
27、rol and data management Systems Engineering and Analysis. Mission Operations and Ground Support Systems.Training and simulation systems Mission Operations and Ground Support Systems.Logistics and maintenance Mission Operations and Ground Support Systems.Launch support systems Mission Operations and
28、Ground Support Systems. Integration and Testing Manufacturing and Assembly Engineering Design (Phase C/D).Spacecraft and Spacecraft Instruments Engineering Design (Phase C/D).Software Engineering Engineering Design (Phase C/D). Systems Engineering and Analysis.Engineering design and project processe
29、s and standards Program Management. Safety and Mission Assurance.Configuration Change Control Safety and Mission Assurance.Product Assurance Safety and Mission Assurance.Review systems and boards Additional Categories. Additional Categories.Configuration Management Additional Categories.Energetic Ma
30、terials - Explosive/Propellant/Pyrotechnic Additional Categories.Hardware Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Additional Categories.Parts, Materials, & Processes Additional Categories.Payloads Additional Categories.Procurement, Small Busi
31、ness & Industrial Relations Additional Categories.Safety & Mission Assurance Additional Categories.Test & Verification Safety and Mission Assurance. Additional Info: Project: N/A Approval Info: Approval Date: 2010-12-30 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
