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  1. 1. Introduction to Complex System Engineering Emmanuel FUCHS Slides available soon at www.elfuchs.fr
  2. 2. Complex System Examples Information Systems
  3. 3. System Problems Examples
  4. 4. System Problems Examples
  5. 5. System definition (Eberhardt Rechtin 1926-2006) • A system is a construct or collection of different elements that together produce results not obtainable by the elements alone. • The elements, or parts, can include people, hardware, software, facilities, policies, and documents; that is, all things required to produce systems-level results. • The results include system level qualities, properties, characteristics, functions, behavior and performance. • The value added by the system as a whole, beyond that contributed independently by the parts, is primarily created by the relationship among the parts; that is, how they are interconnected.
  6. 6. Systemic The whole is greater than the sum of the parts; The part is greater than a fraction of the whole. Aristotle
  7. 7. System: another definition • A system is any set (group) of interdependent or temporally interacting parts. • Parts are generally systems themselves and are composed of other parts, just as systems are generally parts of other systems.
  8. 8. System Definition Mission Users System Sub Border System Sub System Sub System Stakeholders Environment
  9. 9. System Meta Model From INCOSE
  10. 10. SE Bodies • http://www.afis.fr/ – Association Française d'Ingénierie Système • http://www.incose.org/ – International Council on Systems Engineering (INCOSE)
  11. 11. System Engineering Definition “an interdisciplinary approach encompassing the entire technical effort to evolve and verify an integrated and balanced set of system, people, product, and process solutions that satisfy customer needs…..”
  12. 12. System Engineering (SE) • SE focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the complete problem • Systems engineers deal with abstract systems, and rely on other engineering disciplines to design and deliver the tangible products that are the realization of those systems. • Systems engineering effort spans the whole system lifecycle.
  13. 13. Systemic Approach • One + One > two • Aristotle : The whole is more than the sum of its parts. – Parts (Components) – Connections
  14. 14. System Engineering Meta Model From INCOSE
  15. 15. System engineer/architect • Works with system abstraction. – It is impossible to master everything • Requirements Management • System Model
  16. 16. Design the right system
  17. 17. Design the right system As proposed by the project sponsor
  18. 18. Design the right system As proposed by As specified in the the project sponsor project request
  19. 19. Design the right system As proposed by As specified in the As designed by the project sponsor project request the project analyst
  20. 20. Design the right system As proposed by As specified in the As designed by the project sponsor project request the project analyst As proposed by the programmers
  21. 21. Design the right system As proposed by As specified in the As designed by the project sponsor project request the project analyst As proposed by As installed at the programmers the users’ site
  22. 22. Design the right system As proposed by As specified in the As designed by the project sponsor project request the project analyst As proposed by As installed at What the customer the programmers the users’ site really want
  23. 23. Process Definition • Set of interrelated of interacting activities which transforms inputs to outputs Inputs Outputs P
  24. 24. A Process
  25. 25. Process: V cycle
  26. 26. Sequential V cycle drawbacks Documentation And mock-up Phase
  27. 27. Sequential V cycle drawbacks Documentation And mock-up Phase
  28. 28. Iterative and Incremental Iterative Incremental
  29. 29. Barry W. Boehm
  30. 30. Iterative and Incremental • The Systems Engineering Process is not sequential. It is parallel and iterative. • The complex interrelationship between creating and improving models throughout the process of developing and selecting alternatives is a good example of the dynamic nature of the systems engineering process.
  31. 31. Process Standardization • NASA • DOD (US Departement Of Defense): – Documentation Model • IEEE • ISO (International Organization for Standardization) • IEC (International Electrotechnical Committee). – ISO/IEC 15504 / SPICE (Software Process Improvement and Capability dEtermination) • SEI (Software Engineering Institute)
  32. 32. Capability Maturity Model - Integration • CMMI defines the essential elements of effective processes for engineering disciplines based on best industry experiences. • CMMI models provide guidance when developing and evaluating processes. • CMMI models are not actually processes or process descriptions.
  33. 33. CMMI Maturity Levels Level Identified as Status 5 optimizing focus on process improvement quantitatively 4 managed process measured and controlled process characterized for the organization 3 defined and is proactive process characterized by projects and often 2 managed reactive process uncontrolled poorly managed and 1 initial reactive
  34. 34. Process Documentation and Review • SSS: System/Segment Specification • SSDD : System/Segment Design Document • IRS : Interface Requirement Specification • ICD : Interface Control Definition • SRR : System Requirement Review • SDR : System Design Review • TRR : Test Readiness Review
  35. 35. Process Activities
  36. 36. What is a requirement ? • A requirement is a condition to be satisfied in order to respond to: – A contract – A standard – A specification – Any other document and / or model imposed.
  37. 37. Requirements • User’s Requirements – Statements in natural language of the system services. – Described by the user • System Requirements – Structured document setting out detailed description of system services. – Part of the contract
  38. 38. User’s Requirements example • A customer must be able to abort a transaction in progress by pressing the Cancel key instead of responding to a request from the machine. • The washing machine will be used in the following countries: UK, USA, Europe, Eastern Europe
  39. 39. Process
  40. 40. System Requirements • The System shall provide ........ • The System shall be capable of ........ • The System shall weigh ........ • The Subsystem #1 shall provide ........ • The Subsystem #2 shall interface with .....
  41. 41. Requirement Quality • A good requirement states something that is necessary, verifiable, and attainable • To be verifiable, the requirement must state something that can be verified by: – analysis, inspection, test, or demonstration (AIDT)
  42. 42. Requirement analysis • User Requirement – Minimum levels of noise and vibration are desirable. • System Requirement – Requirement 03320: The noise generated shall not exceed 60 db
  43. 43. Requirement Types • Functional requirements – Functional requirements capture the intended behavior of the system. – This behavior may be expressed as services, tasks or functions the system is required to perform • Non-Functional requirements – All others • Constraints
  44. 44. Process
  45. 45. System Architecture • The System Architecture identifies all the products (including enabling products) that are necessary to support the system and, by implication, the processes necessary for development, production/construction, deployment, operations, support, disposal, training, and verification
  46. 46. Architecture Modeling • System : Abstraction – Functional model – Dynamic model – Semantic Model – Object model – Physical Model – Interfaces Model • Model Views
  47. 47. Architecture Meta Model From IEEE
  48. 48. Architecture and Components Assembly
  49. 49. Example of Architecture Views • The Functional Architecture – identifies and structures the allocated functional and performance requirements. • The Physical Architecture – depicts the system product by showing how it is broken down into subsystems and components
  50. 50. Functional To Physical Model • Functional : Discover the system functions • Washing Machine – What it does ? • Washes – How it does ? • Agitates – Physical Component : Agitator
  51. 51. Functional VS physical Model • How to fly ? • Look at birds: Physical Model • So I need: Legs, Eyes, Brain, and Wings. • But I can not fly !!! • Why ? • I have to find the flight functional model !
  52. 52. Flying functional model • Functional decomposition of flying function: – Produce horizontal thrust, – Produce vertical lift. – Takeoff and land, – Sense position and velocity, – Navigate,
  53. 53. Example Birds physical for flying • Physical decomposition: – physical components that birds used to fly: Legs, Eyes, Brain, and Wings. • But can not be applied to system directly
  54. 54. Bird and Airplane Functional to Physical architecture Airplane Physical Bird Physical Function Component Component Takeoff and land Wheels, Legs Sense position and Vision or radar Eyes velocity Navigate Brain or computer Brain Produce horizontal Propeller or jet Wings thrust Produce vertical lift Wings Wings
  55. 55. Multi-criteria decision
  56. 56. Trade Off • Multi-criteria decision-aiding techniques are available to help discover the preferred alternatives. • This analysis should be repeated, as better data becomes available.
  57. 57. Washing Machine example
  58. 58. Context Diagram
  59. 59. Washing Machine Functional Breakdown
  60. 60. Washing Machine Data Flows
  61. 61. Washing Machine Physical Model agitator plungers tube draining hand-operated washer
  62. 62. Washing Machine Physical Model agitator US top loading Outer tube draining
  63. 63. Washing Machine Physical Model top loading
  64. 64. Washing Machine Physical Model Inner tube = drum Outer tube agitator draining front loading Europe
  65. 65. Washing Machine Physical Model front loading
  66. 66. Washing Machine Physical Model front loading
  67. 67. Process
  68. 68. Integration • Integration means bringing things together so they work as a whole.
  69. 69. Spaghetti Plate Syndrome
  70. 70. Spaghetti Plate Syndrome
  71. 71. Spaghetti Plate Syndrome
  72. 72. Spaghetti Plate Syndrome
  73. 73. Spaghetti Plate Syndrome
  74. 74. Spaghetti Plate Syndrome
  75. 75. Spaghetti Plate Syndrome Spaghetti Plate
  76. 76. Spaghetti Plate Syndrome System Architect Spaghetti Plate
  77. 77. Spaghetti Plate Syndrome System Integrator System Architect Spaghetti Plate
  78. 78. Encapsulation Analogy A driver doesn't care of engine's internal working. He only knows the interface Implementation Interface
  79. 79. Process
  80. 80. IVVQCA • Integrate : – Build the system • Verification : – Ensures that you built it right • Validation : – Ensures that you built the right thing • Certification : – Ensure that the system is safe • Acceptance : – Ensures that the customer gets what he wants and the company get paid.
  81. 81. Ensure that the system is safe
  82. 82. Conclusion Thank You For Your Attention Questions are welcome Contacts : emmanuel.fuchs@thalesraytheon-fr.com Slides Available soon at www.elfuchs.fr