System Architecting

1. System Architecting CPDA – D6 Foundation of Systems Engineering

2. Conventional Engineering Design Paradigm • Traditional engineering tends to jump to design solutions very early in the process of problem definition (and solving) and fixes the unintended emergence as and when it occurs • There is a strong pre-disposition to re-use and adapt existing design solutions • This commitment to a specific solution architecture occurs early in the requirements definition stage and is very difficult to depart from • Innovation is as often driven by technical enthusiasm as much as by user need • The operating paradigm is generally evolutionary – stepwise advance generation by generation. In conventional system design The System of Interest and its configuration are the Centre of Interest CPDA – D6 Foundation of Systems Engineering

3. The Focus Is On The System To Be Deployed Source : Martin, J., 2004, The Seven Samurai of Systems Engineering, INCOSE International Conference – on UWEOnline Source : Martin, J., 2004, The Seven Samurai of Systems Engineering, INCOSE International Conference – on UWEOnline CPDA – D6 Foundation of Systems Engineering

4. The Focus Is On The System To Be Deployed The System of Interest Source : Martin, J., 2004, The Seven Samurai of Systems Engineering, INCOSE International Conference – on UWEOnline Source : Martin, J., 2004, The Seven Samurai of Systems Engineering, INCOSE International Conference – on UWEOnline CPDA – D6 Foundation of Systems Engineering

5. The Focus is Generally on the System of Interest Containing system Look at the Interactions System System System of Interest A B System What are the interactions required with the System of Interest These are the STAKEHOLDER or USER REQUIREMENTS CPDA – D6 Foundation of Systems Engineering

6. However We Need to Understand The Interactions and Opportunities Containing system Do the Stakeholders Know? Look at the Interactions System But Is the Boundary Right? System First Treat the System of Interest as a Black Box System of Interest A B System White box analysis CPDA – D6 Foundation of Systems Engineering

7. Explore The Robustness of the Requirements • Perceptions of need are often framed against a conscious or unconscious pre-disposition to a particular solution • Challenge that by proposing alternate solutions to explore the stated needs • If the requirements appear stable perhaps challenge that stability with bizarre alternatives • Try and mine the stated requirements as initially stated to bring out the underlying needs (or aspiration) that the candidate has revealed • A test for a very robust requirement is that it survives intact with a wide variety of candidate solutions • If not – why not? CPDA – D6 Foundation of Systems Engineering

8. Containing system Containing system Containing system Containing system Look at the Interactions Look at the Interactions Look at the Interactions Look at the Interactions System System System System System System System System First Treat the System of Interest as a Black Box First Treat the System of Interest as a Black Box First Treat the System of Interest as a Black Box First Treat the System of Interest as a Black Box System of Interest System of Interest System of Interest System of Interest A A A A B B B B System System System System The Use of Candidates Solutions Can Facilitate Understanding If some candidates do not meet the emerging stakeholder requirements – they have still served a purpose!! CPDA – D6 Foundation of Systems Engineering

9. But Be Careful…….. • The candidate solutions considered are often only increments of the existing solutions • Extension of an existing design • A development of what the customer already uses • The frame of reference often constrains the solution space to an low margin incremental opportunity • Consider taking the analysis up a level to consider the “System of Systems” issues • Question the stakeholders to understand their “stakeholders” needs – the childlike “Why?” has its merits! So Where Is This Particularly Important? CPDA – D6 Foundation of Systems Engineering

10. Strategic (Enterprise) Architecting - Airbus CPDA – D6 Foundation of Systems Engineering

11. Mechanical Power Mechanical Power Mechanical Power Mechanical Power Command Command Command Command Electrical Power Electrical Power Electrical Power Electrical Power Integrated Integrated Integrated Integrated Integrated Hydraulic Power Hydraulic Power Hydraulic Power Hydraulic Power Power Power Power Power Power Fuel Fuel Fuel Fuel Systems Systems Systems Systems Systems Bleed Bleed Bleed Bleed Solutions Solutions Solutions Solutions Solutions Thrust Thrust Thrust Thrust Engine Health Data Engine Health Data Engine Health Data Engine Health Data Air Air Air Air Flight Data Flight Data Flight Data Flight Data Customer Outputs Customer Outputs Rolls Rolls - - Royce Design Authority Royce Design Authority Not Rolls Not Rolls - - Royce Design Authority Royce Design Authority Integrated Power Systems – Rolls Royce Conventional Power System • Engine provides thrust plus mechanical & pneumatic power. • Aircraft systems transform mechanical power into electrical/hydraulic power. • System components individually optimised, system functionally integrated. Integrated Power System • IPS provides thrust plus mechanical, electrical, pneumatic & hydraulic power. • Aircraft systems define demand for power which is interpreted by the IPS Resource Manager. • System components are designed to deliver optimal system performance. Source : INCOSE BLG Presentation – Sept 2004 – Gordon Warnes, Rolls Royce CPDA – D6 Foundation of Systems Engineering

12. Candidate Architecture • Getting this right is critical to success • Modelling can support decision-making • “Expert” viewpoints are a critical success factor • The further the departure from the norm the higher the risks but offset by potentially much higher returns • Early Risk Reduction becomes dominant paradigm for innovative lines of development CPDA – D6 Foundation of Systems Engineering

13. To Take the Analysis Further We Need to Open the Box and Start Testing the Architecture Now We Need to Open the Box Containing system System System System of Interest A B System White box analysis CPDA – D6 Foundation of Systems Engineering

14. With the Candidate Architectures • Once the initial stakeholder requirements (including in house ones) are exposed the candidate systems of interest can then be explored from a wide range of viewpoints • Manufacture – Does it use the existing infrastructure? • Use – Will the customer need to collaborate? • Support – Who is providing it? • Maintenance – Are we paying? • Misuse – Is it vulnerable? • Retirement – Can we recycle/reuse it? • Disposal – Are there new hazards? • etc.????? • The ambition is to achieve an understanding of both desirable and undesirable interactions. These will be dependent on the system architecture ultimately chosen and in reality are often determinants of it CPDA – D6 Foundation of Systems Engineering

15. GENERAL COMMITTEE employers Too much work due to increased role How can we get a better service? We need to automate members education secretary secretary 100 test centres manual filing system I hope we don’t get computers exams accountant students education assistant D E Avison & G Fitzgerald, Information Systems Development, 2nd ed (McGraw-Hill, 1995),Fig 4.2 Remember Rich Pictures Help to Illuminate Interactions CPDA – D6 Foundation of Systems Engineering

16. Life-Cycle Views • What is required of the system of interest over time • What is the proposed system replacing? • What is its predecessor doing • What new is needed • When will it be needed? • How will it be introduced? • How will it be supported? • When will it be replaced? Again some of these issues will reveal constraints which will ultimately lead to certain candidates being unviable CPDA – D6 Foundation of Systems Engineering

17. The Systems Engineering Life- Cycle Standard – ISO15288 Need to be Considered at the Stakeholder Requirements and Architecting Stages CPDA – D6 Foundation of Systems Engineering

18. Who designs these? Who designs these? So Now We Know What’s Wanted – What Next? – System Requirements Containing system Attributes of A-B interactions Attributes of interactions with other systems System Attributes of A Attributes of B System System of Interest A B System CPDA – D6 Foundation of Systems Engineering

19. So Now We Know What’s Wanted – What Next – System Requirements We now have more Black Boxes at a Lower Level in the Hierarchy!! Containing system System System System of Interest Black Box 1 Black Box 2 System WHITE BOX CPDA – D6 Foundation of Systems Engineering

20. Developing the Systems Resqirement Document (SRD) Often Forms Part of a Concept Study • SRD Development is a fluid process • Often driven by Simulation, Modelling, Scenario Investigation, Review of Technology Options • The objective is to determine the risk, cost, return balance to develop a realistic SRD which can be costed • This phase is often undertaken in a separate contract often led be a party who is barred from bidding for the main contract • In a non-contractual environment it may be led by a team of experts drawn from the lead company and its suppliers and run as a discrete activity CPDA – D6 Foundation of Systems Engineering

21. A Typical Process for System Requirements Maturation Note The Feedback Loop CPDA – D6 Foundation of Systems Engineering

22. Heuristics (Guides) Can Be Used to Assist Architectural Development - A Challenge!! • The team that created and built the present successful product is often the best for its evolution but seldom for creating its replacement • If you don’t understand the present system you can’t be sure you’re re-architecting a better one • When implementing a change keep some elements constant to provide an anchor point Source : Maier, M. and Rechtin, E (2003); The Art of Systems Architecting, CRC Press CPDA – D6 Foundation of Systems Engineering

23. Heuristics (Guides) Can Be Used to Assist Architectural Development - A Challenge!! • A good design has benefits in more than one area • System quality is defined in terms of customer satisfaction not requirements satisfaction • If you think your design is perfect it is only because you haven’t shown it to someone else • “Proven” and “State of the Art” are mutually exclusive qualities Source : Maier, M. and Rechtin, E (2003); The Art of Systems Architecting, CRC Press CPDA – D6 Foundation of Systems Engineering

24. You will find hundreds of these in Maier and Rechtin’s book!! However the production of a viable system still depends on engineering the detail right…………….. CPDA – D6 Foundation of Systems Engineering

25. Reliability Model “Customer” Requirement URD Determine failure modes & mechanisms FMEA CURRENT_PRICES Intelligent SEEDS BUDGET WEATHER Lawn mower SOIL_QUALITY PURCHASED_FERTILIZER PURCHASE ü Operational ... Functional ….. Non - Functional …. PURCHASED_SEEDS 1 PLANTS CULTIVATE 1 Textual Analysis 2 WATER PURCHASED_HEALTH_ITEMS Determine design reliability HEALTH_ITEMS Fault Tree Analysis PICK VEGETABLE COMPOST VEGETABLES Capture stated customer requirements and determine Key Requirements 3 DIAGRAM 0 supply ü ü 2.1 EXTRACT HOME_GROWN_SEED SEED 4 machine Viewpoint Analysis Criteria cutting user Material M’fcture Time to Reliability Safety Load Overall maintenance Determine product/system functionality Y = f and Structure requirements process 2.2 interaction ü ü cost cost produce carrying Satisfaction QFD 2 Update Functional Model DOORS Functional Modelling Weighting 0.10 0.20 0.05 0.25 0.3 0.1 1.0 Requirements-concept solution compliance and determine sub system targets 2.3 ü ü Develop a functional model of the product/system Y= f(x) to identify logical interfaces Schemes Generate DOORS database Decision Matrix internal Built-up supply 90% 80% 80% 90% 80% 90% CURRENT_PRICES navigation cutting SEEDS management BUDGET plates power WEATHER 2.4 Evaluate whole concepts against CTQs for further down-selection ü ü SOIL_QUALITY PURCHASED_FERTILIZER welded PURCHASE PURCHASED_SEEDS 1 9 16 4 22.5 24 9 84.5 PLANTS CULTIVATE 80% 50% 75% 80% 80% 80% 2 PURCHASED_HEALTH_ITEMS WATER Cast hook HEALTH_ITEMS Acceptance Test Spec 10 10 3.7 20 24 8 75.7 Built-up 90% 90% 90% 90% 80% 90% PICK Generate acceptance criteria VEGETABLE COMPOST VEGETABLES 3 ü 2.5 ü plates DIAGRAM 0 EXTRACT HOME_GROWN_SEED collect SEED Receiving Function Sensitivity to flow riveted Flow 4 determine sense sense drive and 9 18 4.5 22.5 24 9 86.5 Sensitivity Analysis X 1.1  y 1.2  w 2.2.1  u 2.3.1 etc QFD 1 Function Means Analysis cut grass grass position obstacles lawn state manoeuvre x cuttings 2.6 x Assess the functional sensitivity and potential functional failure modes to give an early risk assessment x x Identify means of achieving functionality Containment Card reader Optional Lan Wipe clean Coin handling Key pad Display Design Requirements Whole concept Selection Importance to Customer Customer Requirements Easy to use 4 Features Multi-language 3 3 5 Coin/card/credit 5 Durable Determination of whole concept solutions Reliable 4 Operation N2 Analysis self Cleans easily 2 learning Maintainable 5 monitor European Arabic 95% validation 16 max 1M ops Assess degree of natural functional binding and coupling to identify natural Architecture and system redundancy 3 min min ingress All standard 500k inserts luminosity 1kN shock Target values Correlate and cross check requirements for completeness and consistency Technical competitive assessment Importance Weighting 39 82 58 139 126 50 18 Once The Architecture Is Set (or Postulated) Then The Conventional SE Tools Come into Play To Design, Develop and Verify Source : INCOSE BLG Presentation – Sept 2004 – Gordon Warnes, Rolls Royce CPDA – D6 Foundation of Systems Engineering