0
CONFIDENTIAL        System Requirements Analysis:The first step to value-based system development                         ...
CONFIDENTIALINNOVATIONDAY 2011   Slide 2
CONFIDENTIAL      What is a system requirement?                 1. A need: a process or improvement, that                 ...
CONFIDENTIAL      The bridge function of requirements                                       Requirements     Stakeholders ...
CONFIDENTIAL      For who are requirements important?                             Stakeholders                            ...
CONFIDENTIAL      Users: The system must create Added Value       • What is the Added value of your product/system?       ...
CONFIDENTIAL      What is the importance of requirementsINNOVATIONDAY 2011          Slide 7
CONFIDENTIAL      Importance of adequately defining the      requirements        If you cannot manage to define the requir...
CONFIDENTIAL      Importance of ‘good’ requirements        Conclusion: Leffingwell & Widrig (2003): Of the total budget fo...
CONFIDENTIAL       Criteria for well-defined requirements       Completeness:                      No missing requirements...
CONFIDENTIAL       Criteria for well-defined requirements       Unambiguity:                     • Only 1 interpretation p...
CONFIDENTIAL       Requirements Analysis issues                     The first step in the system engineering process:     ...
CONFIDENTIAL       System Requirements Analysis         In the traditional waterfall model of system development, the firs...
CONFIDENTIAL      The System Engineering ProcessINNOVATIONDAY 2011         Slide 14
CONFIDENTIAL       Origin Process Inputs                                 Analyze all aspects of the entire system life cyc...
CONFIDENTIAL      Key System Requirements      • Operational :      Where will the system be used?      How long will the ...
CONFIDENTIAL       Break-down requirements     • Items to be Developed: These are the primary requirements that will creat...
CONFIDENTIAL       Holistic approach                                      • Define the Functional & Performance           ...
CONFIDENTIAL      Define functional and performance requirements        Functional requirements: What the system must do… ...
CONFIDENTIAL      Constraints & Interfaces                      Define design constraints:                      Limit Desi...
CONFIDENTIAL                                      Traffic Light                                                           ...
CONFIDENTIAL     Break-down requirements      Security System for the Traffic Controller (Traffic Lights)      Functional ...
CONFIDENTIAL     Design constraints      • Easy serviceability & maintainability      • Minor Assembly efforts      • Re-u...
CONFIDENTIAL     Interface requirements      Routing the Error Messages to a Remote Central Security System      Receiving...
CONFIDENTIAL      Functional Analysis & Allocation  •     Clearly define the Global Framework and the different sub module...
CONFIDENTIAL Functional Analysis Tool: FAST diagramINNOVATIONDAY 2011       Slide 26
CONFIDENTIAL      Result: Functional Architecture   A Simple Rule:          Look to see if all the functions are verbs. If...
CONFIDENTIAL      Refine Interface architectureINNOVATIONDAY 2011            Slide 28
CONFIDENTIAL      Synthesis         Convert system architectures from Functional to Physical     • Physical decomposition ...
CONFIDENTIAL      Morphological map      Alternative Design Concepts        Alternative concepts can be defined via a Morp...
CONFIDENTIAL      Example: Mobile PhoneINNOVATIONDAY 2011            Slide 31
CONFIDENTIAL               It is challenging to fix the concept, that will create the most Added               Value in re...
CONFIDENTIAL      System Analysis and Verification           • Diverge: create a spectrum of requirements, sub-modules, fu...
CONFIDENTIAL          System Specifications      •        Add the Secundary Development Items      •        Clearly define...
CONFIDENTIAL                     helps companies and governments                     to innovate. We design products      ...
Upcoming SlideShare
Loading in...5
×

Verhaert Innovation Day 2011 – Joris Vanderschrick (VERHAERT) - System Requirements Analysis

194

Published on

Speaker of Verhaert at the 8th edition of our Innovation Day on October 21st 2011.

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
194
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
3
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Verhaert Innovation Day 2011 – Joris Vanderschrick (VERHAERT) - System Requirements Analysis"

  1. 1. CONFIDENTIAL System Requirements Analysis:The first step to value-based system development Joris Vanderschrick Verhaert - Embedded Systems Development Joris.vanderschrick@verhaert.comINNOVATIONDAY 2011 Slide 1
  2. 2. CONFIDENTIALINNOVATIONDAY 2011 Slide 2
  3. 3. CONFIDENTIAL What is a system requirement? 1. A need: a process or improvement, that stakeholders want to realize through a system. 2. A demand to a system: the behavior (= functionality) or quality (= performance) that a system must have to fulfil the need of the stakeholders. Uit: Handboek RequirementsINNOVATIONDAY 2011 Slide 3
  4. 4. CONFIDENTIAL The bridge function of requirements Requirements Stakeholders -) Business -) Customer -) Users … Development Team • Requirements: What the system must be able to do… • Stakeholders: …to optimally be able to support us • Development team: …and we have to implement themINNOVATIONDAY 2011 Slide 4
  5. 5. CONFIDENTIAL For who are requirements important? Stakeholders Service Provider Customer Requirements Development USERS Team Testers/ ValidationINNOVATIONDAY 2011 Slide 5
  6. 6. CONFIDENTIAL Users: The system must create Added Value • What is the Added value of your product/system? Feasibility Utility Added Value Desirability Usability Alowability The ‘requirements’ must enable the developed system concept to create Added Value for the end- userINNOVATIONDAY 2011 Slide 6
  7. 7. CONFIDENTIAL What is the importance of requirementsINNOVATIONDAY 2011 Slide 7
  8. 8. CONFIDENTIAL Importance of adequately defining the requirements If you cannot manage to define the requirements at the start of a project, than it does not matter anymore how good you execute the following actions. Phase Relative Correction costs Requirements 1‐2 Technical Concept 5 Realisation 10 Unit Test 20 Acceptance Tst 50 Maintenance 50 Davis (1993)INNOVATIONDAY 2011 Slide 8
  9. 9. CONFIDENTIAL Importance of ‘good’ requirements Conclusion: Leffingwell & Widrig (2003): Of the total budget for (software) development tasks, 25 to 40% will be spent on the correction of errors in the requirements.INNOVATIONDAY 2011 Slide 9
  10. 10. CONFIDENTIAL Criteria for well-defined requirements Completeness: No missing requirements: All the requirements, that the system must fulfil, must be defined Consistency: No conflicting requirements: Requirements can conflict when stakeholders have different opinions about the specific demands for the systemsINNOVATIONDAY 2011 Slide 10
  11. 11. CONFIDENTIAL Criteria for well-defined requirements Unambiguity: • Only 1 interpretation possible of the requirements. • Not 100% possible Written in natural language Validity: Requirements are only valid if they contribute to the added value for the stakeholders “Around 45% of the developed functionality for a system is never used!” “Don’t waste time with the overkill functionality.“ The Standish Group, 2003INNOVATIONDAY 2011 Slide 11
  12. 12. CONFIDENTIAL Requirements Analysis issues The first step in the system engineering process: REQUIREMENTS ANALYSISINNOVATIONDAY 2011 Slide 12
  13. 13. CONFIDENTIAL System Requirements Analysis In the traditional waterfall model of system development, the first phase of requirements analysis is also the most important one. Goal: • Understanding the customers business context and constraints • Functions the product must perform • The performance levels it must adhere to • The external systems it must be compatible withINNOVATIONDAY 2011 Slide 13
  14. 14. CONFIDENTIAL The System Engineering ProcessINNOVATIONDAY 2011 Slide 14
  15. 15. CONFIDENTIAL Origin Process Inputs Analyze all aspects of the entire system life cycle including all equipments touch points with consumers, installers, service & maintenance staff Customer Needs Objectives 1. Customer Needs/Objectives/Demands Demands • Goals • Measures of Effectiveness • Environments Attract • Constraints Retain Choose 2. Other: • Technology Base Support Use • Output Requirements from Prior Development Effort • Requirements Applied Through Specifications and StandardsINNOVATIONDAY 2011 Slide 15
  16. 16. CONFIDENTIAL Key System Requirements • Operational : Where will the system be used? How long will the system be in use by the user? • Environmental: How are the various system components to be used? Utility! What environments will the system be expected to operate in an effective manner? • Goal: How will the system accomplish its mission objective? Added Value! • Performance: What are the critical system parameters to accomplish the goal? How effective or efficient must the system be in performing its goal?INNOVATIONDAY 2011 Slide 16
  17. 17. CONFIDENTIAL Break-down requirements • Items to be Developed: These are the primary requirements that will create the added value of the system. The biggest development efforts are initiated to fulfil these requirements. • Specifications: Secundary development Items: These are the quantified requirements that do not need much development effort. They can immediately be fulfilled by existing components or sub-systems. Usually purchasing parts.INNOVATIONDAY 2011 Slide 17
  18. 18. CONFIDENTIAL Holistic approach • Define the Functional & Performance requirements • Define Design constraints • Define the Interface requirementsINNOVATIONDAY 2011 Slide 18
  19. 19. CONFIDENTIAL Define functional and performance requirements Functional requirements: What the system must do… Performance requirements: How well the system must perform… Break-down of the ITDINNOVATIONDAY 2011 Slide 19
  20. 20. CONFIDENTIAL Constraints & Interfaces Define design constraints: Limit Design flexibility Environmental conditions & limits Standards Interface requirements: Define the functional and physical interfaces to external or higher-level and interacting systems.INNOVATIONDAY 2011 Slide 20
  21. 21. CONFIDENTIAL Traffic Light IPC Controller Remote Security Central for System coordination Interface System between traffic lightsSecurity System for the Traffic Light Controller & Central for coördination Customer Customer Requirements Requirements Functional Performance Interface Functional Performance Interface Requirements Requirements Requirements Requirements Requirements Requirements INNOVATIONDAY 2011 Slide 21
  22. 22. CONFIDENTIAL Break-down requirements Security System for the Traffic Controller (Traffic Lights) Functional Requirements: • Polling the Traffic Controller for Error • Analysis of the Error Messages • Routing the Error Messages to a Remote Central Security System Performance Requirements: • Polling speed (@1Hz) • Data transfer speed Error report available at remote system within 20 seconds • Redundant Interface System Functional Requirements: • Receiving commands of the central system for the coordination of the Traffic Lights • Translating the specific command towards the protocol of the Traffic Controller Performance Requirements: • Reaction time between command & traffic lights change: <3 secondsINNOVATIONDAY 2011 Slide 22
  23. 23. CONFIDENTIAL Design constraints • Easy serviceability & maintainability • Minor Assembly efforts • Re-use known company plaforms: Cirrus Logic ARM • Easy accessiblity • IP-67 • No internal Airflow • System temperature up to 70°C. • Migration options for future communication upgrades • EN-50129 Safety related electronic systems for signalingINNOVATIONDAY 2011 Slide 23
  24. 24. CONFIDENTIAL Interface requirements Routing the Error Messages to a Remote Central Security System Receiving commands of the central system for the coordination of the Traffic Lights • Functional: IPC communication network to the Security & Interface system • Physical layer: Long-range wireless network or installed cable infrastructure Polling the Traffic Controller for Error • Functional: IPC communication network to the Traffic Controller • Physical layer: Short-range wireless networkINNOVATIONDAY 2011 Slide 24
  25. 25. CONFIDENTIAL Functional Analysis & Allocation • Clearly define the Global Framework and the different sub modules • Define successively lower-level functions • Allocate Performance and other limiting requirements • Defining/Refine functional architectures at ever-increasing levels of detail • Refine the Internal/External Functional InterfacesINNOVATIONDAY 2011 Slide 25
  26. 26. CONFIDENTIAL Functional Analysis Tool: FAST diagramINNOVATIONDAY 2011 Slide 26
  27. 27. CONFIDENTIAL Result: Functional Architecture A Simple Rule: Look to see if all the functions are verbs. If there is a function identified as a noun, then there is a problem with the understanding of the functions.INNOVATIONDAY 2011 Slide 27
  28. 28. CONFIDENTIAL Refine Interface architectureINNOVATIONDAY 2011 Slide 28
  29. 29. CONFIDENTIAL Synthesis Convert system architectures from Functional to Physical • Physical decomposition defines the physical elements needed to execute the function. • Define preferred physical solutions for the Primary and Secondary Development Items • Define Internal and External Physical Interfaces • Define Alternative System Concepts (Morphological map)INNOVATIONDAY 2011 Slide 29
  30. 30. CONFIDENTIAL Morphological map Alternative Design Concepts Alternative concepts can be defined via a Morphological map that provides a structure overview of the different Items to Be Developed (ITD’s) and the different options to develop them. to a correct Risk ProfileINNOVATIONDAY 2011 Slide 30
  31. 31. CONFIDENTIAL Example: Mobile PhoneINNOVATIONDAY 2011 Slide 31
  32. 32. CONFIDENTIAL It is challenging to fix the concept, that will create the most Added Value in respect to a correct Risk profile. This is a very important task when defining the best System conceptINNOVATIONDAY 2011 Slide 32
  33. 33. CONFIDENTIAL System Analysis and Verification • Diverge: create a spectrum of requirements, sub-modules, functions, solutions,… Avoid fixation to 1 or 2 solutions Other options will become variations • Verfication: Verify with the requirements, constraints, main goal, Added Value • Converge: Trade-Off the different solutions and selectINNOVATIONDAY 2011 Slide 33
  34. 34. CONFIDENTIAL System Specifications • Add the Secundary Development Items • Clearly defined specifications and baselines • System Architecture • Concept Design • Decision DatabaseINNOVATIONDAY 2011 Slide 34
  35. 35. CONFIDENTIAL helps companies and governments to innovate. We design products and systems for organizations looking for new ways to provide value for their customers. Hogenakkerhoekstraat 21 We are a leading integrated 9150 Kruibeke (B) product innovation center; creating tel +32 (0)3 250 19 00 technology platforms, developing fax +32 (0)3 254 10 08 new products and business in info@verhaert.com parallel, hence facilitating new- growth strategies for our clients. More at www.verhaert.comINNOVATIONDAY 2011 Slide 35
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×