Systems Engineering at NASA Processes and Requirements

1. Systems Engineering at NASA Processes and Requirements Jim Andary NASA Goddard Space Flight Center James.F.Andary@nasa.gov October 29, 2009

2. Agenda This lecture will be based on the NASA Systems Engineering Processes and Requirements (NPR 7123.1) Included are discussions of the following: The Systems Engineering �Engine� The Systems Engineering Lifecycle Systems Engineering Management Plan (SEMP) Systems Engineering Framework The 17 common technical processes System Design Processes (4) Technical Management Processes (8) Product Realization Processes (5) Technical Reviews Systems Engineering and System Acquisition

3. NPR 7123.1A Scope

4. Why an NPR? To establish a core set of common Agency-level technical processes and requirements needed to define, develop, realize, and integrate the quality of the system products created and acquired by or for NASA. To build upon and apply best practices and lessons learned from NASA, other government agencies, and industry to clearly delineate a successful model to complete comprehensive technical work, reduce program and project technical risk, and improve mission success.

5. The Systems Engineering �Engine�

6. The NPR identifies a core set of 17 common technical processes used by NASA projects in engineering system products. The interaction and flows of these processes are illustrated by the �engine�.

7. Common Technical Processes (The �Engine�)

8. Application of SE Processes

9. Part I page 9 Top-Down Bottom-Up Approach

10. The Systems Engineering Life Cycle

11. System Life Cycle The system life cycle represents the stages of a system�s life Conceiving and developing a mission is a sequence of activities �Crawl before you walk, walk before you run� Numerous definitions of life cycle exist, e.g., ISO/IEC 15288 Stages are characterized by entrance and exit criteria not by time All systems engineering processes apply in all stages of the life cycle The power of the life cycle is based on logically grouping activities together into phases each with a defined output and control gate that guides what is done

12. System Life Cycle �A well-defined systems engineering life-cycle model that is imposed on the system from the beginning can give the maturity derived from lessons learned in using the time-tested model, thus adding an important element of stability to the organizational structure�. [Sage and Rouse, 2009]

13. Typical Life Cycle Representations

14. NASA Program & Project Life Cycles

15. Early Phases of the Life Cycle Have High Payoff

16. Lifecycle Phases

17. The focus of the �Engine� is on a single phase of the life cycle The common technical processes are used to define the elements of a system structure in each applicable phase of the life cycle to generate work products needed to satisfy the exit criteria of the that phase.

19. NASA Life Cycle Process Flow

20. Systems Engineering Management Plan (SEMP)

21. Systems Engineering Management Plan A Systems Engineering Management Plan (SEMP) is used to establish the technical content of the engineering work. The SEMP is written early in the formulation phase for each project and updated throughout the project life cycle. The SEMP provides the communication bridge between the project management team and the technical implementation teams. The SEMP provides the specifics of the technical effort : what technical processes will be used how the processes will be applied using appropriate activities how the project will be organized to accomplish the activities what appropriate work products will be produced the cost and schedule associated with accomplishing the activities.

23. SEMP Content

24. The Systems Engineering Framework

25. NASA Systems Engineering Framework

26. Teamwork Can Prevent This

27. The 17 Common Technical Processes

28. System Design Processes

29. System Design Processes

30. Stakeholder Expectation Definition

31. Stakeholder Expectation Definition

32. Technical Requirements Definition

33. Logical Decomposition

34. Role of Logical Decomposition

35. Design Solution Definition

36. Design Solution Outputs The output of the design solution process is the descriptive documentation for buying, building, coding or assembling & integrating end products. The specific documentation is a function of life-cycle phase and location of the model in the system product breakdown structure (PBS) This documentation is in the form of specifications, drawings, sketches, parts list, etc. Documentation includes initial specifications for subsystems for development of the next lower level PBS models

37. Technical Management Processes

38. Technical Management Processes

39. Technical Planning

40. Requirements Management

41. Allocation & Flowdown of Requirements

42. Interface Management

43. Technical Risk Management

44. Technical Risk Management Probability Risk Assessment (PRA) is a risk assessment technique that quantifies the likelihood of various possible undesired scenarios and their consequences, as well as the uncertainties in the likelihoods and consequences. A risk matrix is a means of managing and communicating risk.

45. Configuration Management

46. Technical Data Management

47. Technical Assessment

48. Measures of Performance Measures of Effectiveness (MOEs) Are derived from stakeholder expectation statements Deemed critical to the mission or operational success of the system Example: Amount of science data to be collected during mission Measures of Performance (MOPs) Broad physical and performance parameters Means of ensuring meeting the associated MOEs Example: Total vehicle mass at launch Technical Performance Measures (TPMs) Typically selected from the defined set of MOEs and MOPs Critical mission success or performance attributes Measurable Progress profile established, controlled and monitored

49. Decision Analysis

50. Product Realization Processes

51. Product Realization Processes

52. Product Implementation

53. Product Integration The product integration process is used to transform the design solution definition into the desired end product through assembly and integration of lower level validated end products in a manner that satisfies the design solution definition requirements (e.g., drawings, specifications)

54. Product Verification The product verification process is used to demonstrate that an end product generated from product implementation or product integration conforms to its design solution definition requirements. �Did I build the system right?� Product verification can be accomplished by test, analysis, demonstration or inspection.

55. Product Validation

56. Product Transition

57. Technical Reviews

58. Technical Reviews

59. Technical Reviews

60. Systems Engineering and System Acquisition

61. References ISO/IEC 15288, Systems engineering � System life cycle processes, 2002 DOD, Systems Management College, Systems Engineering Fundamentals, Fort Belvoir, VA: Defense Acquisition Press, 2001. James N. Martin, Systems Engineering Guidebook: A Process for Developing Systems and Products, 1996. Robert T. Clemen, Making Hard Decisions: An Introduction to Decision Analysis, 2nd edition, Duxbury Press, 1996. Clifford F. Gray and Erik W. Larson, Project Management: The Managerial Process, 2nd edition, McGraw-Hill, 2003.

62. Homework Assignment