This document provides an introduction to complex system engineering. It defines what a system is, provides examples of complex systems like information systems, and discusses key aspects of systems engineering including the system lifecycle, iterative processes, requirements, architecture, integration, and verification and validation. Key definitions and concepts in systems engineering are explained at a high level.

1. Introduction to Complex System Engineering Emmanuel FUCHS Slides available soon at www.elfuchs.fr

3. Complex System Examples Information Systems

4. System Problems Examples

5. System Problems Examples

7. 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.

8. Systemic The whole is greater than the sum of the parts; The part is greater than a fraction of the whole. Aristotle

9. 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.

10. System Definition System Users Mission Environment Stakeholders Border Sub System Sub System Sub System

11. System Meta Model From INCOSE

12. SE Bodies http://www.afis.fr/ Association Française d'Ingénierie Système http://www.incose.org/ International Council on Systems Engineering (INCOSE)

14. 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 …..”

15. 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 .

16. Systemic Approach One + One > two Aristotle : The whole is more than the sum of its parts. Parts (Components) Connections

17. System Engineering Meta Model From INCOSE

18. System engineer/architect Works with system abstraction. It is impossible to master everything Requirements Management System Model

20. Design the right system As proposed by the project sponsor As proposed by the programmers As specified in the project request As designed by the project analyst As installed at the users’ site What the customer really want

22. Process Definition Set of interrelated of interacting activities which transforms inputs to outputs Inputs Outputs P

23. A Process

24. Process: V cycle

25. Sequential V cycle drawbacks Documentation And mock-up Phase

26. Sequential V cycle drawbacks Documentation And mock-up Phase

27. Iterative and Incremental Incremental Iterative

28. Barry W. Boehm

29. 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.

30. 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)

31. 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.

32. CMMI Maturity Levels Level Identified as Status 5 optimizing focus on process improvement 4 quantitatively managed process measured and controlled 3 defined process characterized for the organization and is proactive 2 managed process characterized by projects and often reactive 1 initial process uncontrolled poorly managed and reactive

33. 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. Process Activities

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. 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. 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. Process

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. 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. 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. 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

45. Process

46. 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

47. Architecture Modeling System : Abstraction Functional model Dynamic model Semantic Model Object model Physical Model Interfaces Model Model Views

48. Architecture Meta Model From IEEE

49. Architecture and Components Assembly

50. 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

52. Functional To Physical Model Functional : Discover the system functions Washing Machine What it does ? Washes How it does ? Agitates Physical Component : Agitator

53. 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 !

54. Flying functional model Functional decomposition of flying function: Produce horizontal thrust, Produce vertical lift. Takeoff and land, Sense position and velocity, Navigate,

55. 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

56. Bird and Airplane Functional to Physical architecture mapping Function Airplane Physical Component Bird Physical Component Takeoff and land Wheels, Legs Sense position and velocity Vision or radar Eyes Navigate Brain or computer Brain Produce horizontal thrust Propeller or jet Wings Produce vertical lift Wings Wings

57. Multi-criteria decision

58. 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.

59. Washing Machine example

60. Context Diagram

61. Washing Machine Functional Breakdown

62. Washing Machine Data Flows

63. Washing Machine Physical Model agitator tube draining hand-operated washer plungers

64. Washing Machine Physical Model agitator Outer tube draining top loading US

65. Washing Machine Physical Model top loading

66. Washing Machine Physical Model agitator Outer tube draining Inner tube = drum front loading Europe

67. Washing Machine Physical Model front loading

68. Washing Machine Physical Model front loading

70. Process

71. Integration Integration means bringing things together so they work as a whole.

72. Spaghetti Plate Syndrome

73. Spaghetti Plate Syndrome

74. Spaghetti Plate Syndrome

75. Spaghetti Plate Syndrome

76. Spaghetti Plate Syndrome

77. Spaghetti Plate Syndrome

78. Spaghetti Plate Syndrome Spaghetti Plate

79. Spaghetti Plate Syndrome Spaghetti Plate System Architect

80. Spaghetti Plate Syndrome Spaghetti Plate System Architect System Integrator

81. Encapsulation Analogy Implementation Interface A driver doesn't care of engine's internal working. He only knows the interface

83. Process

84. 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.

85. Ensure that the system is safe

86. Conclusion Thank You For Your Attention Questions are welcome Contacts : [email_address] Slides Available soon at www.elfuchs.fr