Using Requirements-Induced Complexity to Anticipate Development and Integration Problems: Analysis of Past Missions
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The document analyzes the complexity of space mission requirements and the potential for development and integration problems, citing past missions as case studies. It discusses various types of complexities, including structural, functional, and organizational, and highlights the multi-dimensional nature of failure in space projects. Conflicting requirements and unexpected dependencies contribute to the challenges faced in anticipating complexity in these missions.
![©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11
| ©2013 Stevens Institute of Technology10/15/201521
The spacecraft was a partially reusable human
spaceflight vehicle for Low Earth Orbit, which
resulted from joint NASA and US Air Force
efforts after Apollo. “The vehicle consisted of a
spaceplane for orbit and re-entry, fueled by an
expendable liquid hydrogen/liquid oxygen
tank, with reusable strap-on solid booster
rockets. […] A total of five operational orbiters
were built, and of these, two were destroyed
in accidents.”
“Soyuz is a series of spacecraft initially
designed for the Soviet space programme
and still in service today. […] The Soyuz
was originally built as part of the Soviet
Manned Lunar programme. […] The Soyuz
spacecraft is launched by the Soyuz rocket,
the most frequently used and most reliable
Russian launch vehicle to date.”
Source: Wikipedia](https://image.slidesharecdn.com/12aiaa2013presentationalejandrosalado-151015214130-lva1-app6892/85/Using-Requirements-Induced-Complexity-to-Anticipate-Development-and-Integration-Problems-Analysis-of-Past-Missions-21-320.jpg)
Using Requirements-Induced Complexity to Anticipate Development and Integration Problems: Analysis of Past Missions
- 1. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology Date: 10th of September of 2013 By: Alejandro Salado and Roshanak Nilchiani Using Requirements-Induced Complexity to Anticipate Development and Integration Problems: Analysis of Past Missions AIAA SPACE 2013 Conference &Exposition San Diego, CA (USA)
- 2. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20152 Was Apollo a failure?
- 3. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20153 Is Huble Telescope a failure?
- 4. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20154 Was Mars Orbiter a failure?
- 5. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20155 Was Space Shuttle a failure?
- 6. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20156 What is a failure? “Lack of success”
- 7. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20157 Performance target Economic budget Time to market
- 8. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2011 Stevens Institute of Technology8 10/15/2015 Schedule Cost Performance Not compliantCompliant TARGETS Delay Overrun Degraded performance SUCCESS FAILURE CANCEL CANCEL LOSS
- 9. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/20159 Lack of funding Naive estimations Inexistent technologies Many customers Lack of experience Emergent behavior Many contractors Many parts Impossible testing Unexpected dependencies
- 10. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201510 Complexity
- 11. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201511 𝐻 = − 𝑖=1 𝑛 𝑝𝑖 ∙ 𝑙𝑜𝑔2 𝑝𝑖 𝐻 = −𝐾 ∙ 𝑖=1 𝑛 𝑝𝑖 ∙ 𝑙𝑜𝑔𝑗 𝑝𝑖 𝐶 = 𝐶1 + 𝐶2 ∙ 𝐶3 Level of disorder within the system A measure of the constituent parts and their interactions
- 12. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201512 Structural complexity Functional complexity Organizational complexity
- 13. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201513 Category Indices Architecture Science payload, complexity, operations complexity, redundancy, ADCS type, payload instruments, number of thrusters, thermal type, modularity, design standards. Contractual Launch approval, type of customer, multiple sponsors, multiple partners, poor allocation of key functions, lack of well-defines lines of authority, lack of experience. Technology Main stage, orbiter, Earth return vehicle, science payload, space system technology, in situ and sample return technology, sensors and instruments technology, autonomy technology, heritage, BOL/EOL power, solar array area, solar array type, battery type, battery capacity, structures material, ADCS type, solid state memory. Requirements Cruise stage, entry or aeroassist system, descent and landing, rendevouz capture, Earth return vehicle, planetary protection, descent and landing, planetary mobility, ascent vehicle to orbit, ascent vehicle to upper atmosphere, science payload, complexity, lifetime, temperature, pressure, radiation, other environment, spacecraft cost, development time, satellite dry mass, orbit, pointing accuracy, pointing knowledge, uplink band, downlink rate, conflicts, incomplete science requirements, multiple launchers.
- 14. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201514 We can measure the complexity of… Functional architecture Physical architecture Project organization …but we cannot ANTICIPATE the complexity of the PROBLEM!
- 15. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201515 Overall complexity Problem complexity Organiz. complexity Functional complexity Structural complexity 𝐶 𝐶 𝑝, 𝐶𝑓, 𝐶𝑠, 𝐶 𝑜 = − 𝑐 𝑝 𝑐 𝑓 𝑐 𝑠 𝑐 𝑜 𝑃 𝑐 𝑝, 𝑐𝑓, 𝑐 𝑠, 𝑐 𝑜 ∙ 𝑙𝑜𝑔𝑗 𝑃 𝑐 𝑝, 𝑐𝑓, 𝑐 𝑠, 𝑐 𝑜
- 16. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201516 Value level Functions (Do) Performance (Being) Resources (Have) Interaction (Interact) Break-event Req. 1 Req. 2 Req. 3 Req. 4 Req. 5 Req. 6 Req. 7 Goal Req. 8 Req. 9 Wish Req. 10 Req. 11 Req. 12 Functional requirements (Do) What the system does in essence, which includes what it accepts and what it delivers Performance requirements (Being): How well the system does it, which includes performance related to functions the system performs or characteristics of the system on its own, such as –ilities Resource requirements (Have): What the system uses to transform what it accepts in what it delivers Interaction requirements (Interact): Where the system does it, which includes any type of operation during its life-cycle. Source: A. Slado, R. Nilchiani. (2014), A Categorization Model of Requirements Based on Max-Neef’s Model of Human Needs, Syst. Eng., 17: 348-360.
- 17. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201517 …two or more requirements compete for the same resource. …two or more requirements inject opposing directions in laws of physics. ...two or more requirements inject opposing directions in laws of society. …two or more requirements oblige the system to operate in two or more phases of matter. A conflict may exist when…
- 18. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201518 𝐶 𝑝 = 𝑖=1 𝑛 𝑝𝑟𝑖 𝑅𝑅, 𝐼𝑅 + 𝑖=1 𝑚 𝑓𝑟𝑖 𝑅𝑅, 𝐼𝑅 ∙ 𝑚𝑒 𝑎 ∙ 𝑟𝑐 𝑏 ∙ 𝑙𝑝 𝑐 ∙ 𝑙𝑠 𝑑 Performance & Functional Multi-environment Competition for resources Conflicting laws of physics Conflicting laws of society
- 19. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201519 GAO reports are too general Detailed data is confidential Some data is even classified Calibration is needed, but…
- 20. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201520 Publicly known case-study VS Source: Wikipedia
- 21. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201521 The spacecraft was a partially reusable human spaceflight vehicle for Low Earth Orbit, which resulted from joint NASA and US Air Force efforts after Apollo. “The vehicle consisted of a spaceplane for orbit and re-entry, fueled by an expendable liquid hydrogen/liquid oxygen tank, with reusable strap-on solid booster rockets. […] A total of five operational orbiters were built, and of these, two were destroyed in accidents.” “Soyuz is a series of spacecraft initially designed for the Soviet space programme and still in service today. […] The Soyuz was originally built as part of the Soviet Manned Lunar programme. […] The Soyuz spacecraft is launched by the Soyuz rocket, the most frequently used and most reliable Russian launch vehicle to date.” Source: Wikipedia
- 22. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201522 Human (cheap?) access to LEO Fast, frequent, cheap, and safe human access to LEO Fast and frequent access for military satellites Specific military aerodynamic requirements Competitive access for communication satellites Source: Wikipedia
- 23. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201523 Spacecraft Fast Frequent Cheap Safe Military P/L Telecom P/L Military aerod. Space Shuttle No No No No Partially Partially Yes Soyuz Spacecraft Unknown No Yes* Yes N/A N/A N/A
- 24. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201524 Artificial calibration Simplified requirement set Combined funct./perf. requirements Limitations on the case study Subjective assessment 𝐶 𝑝 = 𝑖=1 7 𝑝𝑟/𝑓𝑟𝑖 𝑅𝑅, 𝐼𝑅 ∙ (1 + 𝑒𝑛𝑣𝑖𝑟𝑜𝑛𝑚𝑒𝑛𝑡𝑠)2∙ (1 + 𝑝ℎ𝑦𝑠𝑖𝑐𝑎𝑙 𝑝𝑎𝑟𝑎𝑚)1.3
- 25. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201525 ID Element pr/fr(RR,IR) Environments Physical param. R1 Fast access 3 Space Low prep. time R2 Frequent access 3 Space R3 Cheap access 2 Space Low mass Low volume Low prep. time R4 Safe access 6 Space High mass High prep. time R5 Military P/L 6 Space High mass High volume R6 Telecom P/L 6 Space High mass High volume R7 Military aerodyn. 4 Atmosphere Total amount of conflicts 1 3 𝐶 𝑝 = 𝑖=1 7 𝑝𝑟/𝑓𝑟𝑖 𝑅𝑅, 𝐼𝑅 ∙ (1 + 𝑒𝑛𝑣𝑖𝑟𝑜𝑛𝑚𝑒𝑛𝑡𝑠)2 ∙ (1 + 𝑝ℎ𝑦𝑠𝑖𝑐𝑎𝑙 𝑝𝑎𝑟𝑎𝑚)1.3
- 26. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201526 Alternative R1 R2 R3 R4 R5 R6 R7 Note A1 X X X X X X X Actual Space Shuttle A2 X A3 X X Soyuz Spacecraft A4 X X X X Initial Space Shuttle Concept A5 X X X X X A6 X X X A7 X X X X A8 X X X X X A9 X X X X X A10 X X X X X X 𝐶 𝑝 = 𝑖=1 7 𝑝𝑟/𝑓𝑟𝑖 𝑅𝑅, 𝐼𝑅 ∙ (1 + 𝑒𝑛𝑣𝑖𝑟𝑜𝑛𝑚𝑒𝑛𝑡𝑠)2∙ (1 + 𝑝ℎ𝑦𝑠𝑖𝑐𝑎𝑙 𝑝𝑎𝑟𝑎𝑚)1.3
- 27. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology10/15/201527 Actual Space Shuttle Actual Soyuz Spacecraft Initial Shuttle Design 0 100 200 300 400 500 600 700 800 A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 ProblemComplexity Alternatives
- 28. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | Wrap-up 10/15/201528 ©2011 Stevens Institute of Technology Failure is multi-dimensional Conflicting requirements lead to difficulty Anticipate problem complexity
- 29. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2011 Stevens Institute of Technology10/15/201529 Disclaimer: The views and opinions expressed during this presentation are those of the authors and do not necessarily reflect the official position of the Stevens Institute of Technology or any of its schools.
- 30. ©2011 Stevens Institute of TechnologyP. 2/3 | 01/01/11 | ©2013 Stevens Institute of Technology Stevens Institute of Technology Castle Point on Hudson Hoboken, NJ 07030 w w. s t e v e n s . e d u
Editor's Notes
- #9: Quick overview of 3 primary efforts