1. Principles of Engineering System Design Dr T Asokan asok@iitm.ac.in

2. INTRODUCTION TO SYSTEMS DESIGN Dr T Asokan asok@iitm.ac.in Integration and Qualification

3. Six functions of Design Process 1.Define System Level Design Problem : - Originating requirements developmentDefine System Level Design Problem 2.Develop the system functional architecture 3.Develop the system physical architecture 4.Develop the system operational architecture 5.Develop the interface architecture 6.Define the qualification system for the system : Integration and qualification

4. T Asokan ED309

5. Integration It is the process of assembling the system from its components, which must be assembled from their CIs.

6. Qualification It is the process of verifying and validating the system design and then obtaining the stake holder’s acceptance of the design. Consists of verification, validation and acceptance. Qualification system must be designed simultaneously with the operational system. The exit criterion for integration and qualification is acceptance of the design by the stakeholders

7. Verification, Validation and Acceptance Verification is the determination that the system built was right Validation determine that the right system was built Operational Validity Conceptual validity Requirements validity Design Validity

11. Verification Verification is the matching of CIs, components, subsystems, and the system to their corresponding requirements to ensure that each system has been built right. For verification to be successful, originating and derived requirements must be testable, that is, the requirements must be single statements that are unambiguous, understandable and verifiable.

14. Integration 1. Perform component integration and verification 2. Perform subsystem integration and verification 3. Perform system integration and verification

15. Principal Integration Processes Bottom up - Begins with CIs - After each CI is tested, the components comprising multiple CIs are tested - Process is continued until entire system is assembled and tested - Easier to detect flaws in tiniest pieces of the system - Test conditions are easier to create - Major errors are not caught until the end

16. Top Down - Top level module - Lower levels simulated by stubs - Stubs later replaced by modules - Early demonstration of the system - More productive major flaws occur at the top of the system - Stubs have to be developed - Representation of test case in stubs will be difficult

17. Big Bang (Software industry) - Untested CIs are assembled and the combination is tested - Commonly used and maligned approach - Immediate feedback on the status of system elements is provided - Little or no pre-test planning or training is required - Source of error is difficult to trace

18. Functions in Integration Component Level

19. Inspect and test the CI Identify and fix any correctible deficiencies Assess the impact of any uncorrectable deficiencies Redesign the CI to address deficiencies Redefine the baseline Integrate with the next CI

20. Inspect and test the CI Identify and fix any correctible deficiencies Assess the impact of any uncorrectable deficiencies Redesign the CI to address deficiencies Redefine the baseline Integrate with the next CI