Quality Re Pres Ebert Rudorfer Med Conf2011 V5

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  • 1. Quality Requirements Engineering for Medical Systems MedConf 2011 Munich, 05. October 2011 © 2011 Siemens Healthcare Diagnostics Inc. All rights reserved.© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 1
  • 2. Contents  Goals  Brief Look on Siemens and Vector  Business and Environment  Quality Requirements Engineering  Results and Summary  Further Information© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 2
  • 3. Goals Provide an overview on quality requirements engineering challenges in a medical device project Apply quality requirements engineering for a critical system Share experiences how quality requirements can be successfully addressed Show lessons learned and achieved benefits© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 3
  • 4. Contents  Goals  Brief Look on Siemens and Vector  Business and Environment  Quality Requirements Engineering  Results and Summary  Further Information© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 4
  • 5. Siemens HealthcareIn vivo diagnostics (imaging) X-Ray Computed Magnetic Molecular Ultrasound Oncology Tomography Resonance Imaging IT SolutionsIn vitro diagnostics (laboratory systems) Immunoassay Molecular Clinical Chemistry Hematology Urinalysis Lab Automation Point of Care© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 5
  • 6. Vector Consulting ServicesYour Partner in Achieving Engineering Excellence … offers a comprehensive consulting and training portfolio as well as process tools for Automotive optimizing product development … serves industries such as automotive, Aviation aviation, IT and telecom, machinery and & Defense plants, medical, and railway IT & Telecom … is supporting clients on efficiency improvement, PLM/ALM, functional safety, CMMI/SPICE, requirements engineering and Machinery product management & Plants … as a group serves companies across the Medical world, with over 1000 employees and sales of well over 150 Mio € pa Railway www.vector.com/consulting © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 6
  • 7. Contents  Goals  Brief Look on Siemens and Vector  Business and Environment  Quality Requirements Engineering  Results and Summary  Further Information© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 7
  • 8. Business ChallengesEnvironment:  Shorten time-to-market  Cuts in healthcare budgets  Continuous product innovation© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 8
  • 9. Business ChallengesProduct:Safety-critical: Critical for health andsustainability(e.g. bodily injuries, wrong treatment)Security-critical: Critical forpreserving information integrity(e.g. access to sensitive data)Mission-critical: Critical for missioncontinuity(e.g. unavailability)Business-critical: Critical forbusiness success(e.g. damage to image)Critical need for qualityrequirements engineering© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 9
  • 10. Contents  Goals  Brief Look on Siemens and Vector  Business and Environment  Quality Requirements Engineering  Results and Summary  Further Information© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 10
  • 11. Quality Requirements Engineering (QRE):OverviewQuality Requirements (QR)  A quality requirement describes a qualitative property that a system or individual component of the system must exhibit. Sometimes called: non-functional requirements.  They extend the functional requirements.  Examples: Availability, maintainability, security, reliability.Quality Requirements Engineering (QRE)  The disciplined and systematic approach to elicit, specify, analyze, prioritize, commit, verify, validate, assure and manage quality requirements throughout the life-cycle.  Focus areas: Systems engineering, processes and product life- cycle© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 11
  • 12. QRE: Focus on Systems engineering,processes and product life-cycle Systems Engineering Product Processes Life-Cycle Quality Requirements Engineering (QRE) needs to balance systems perspective and business needs.© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 12
  • 13. Quality Requirements Engineering (QRE):Example: Security Life-Cycle Perspective Life-Cycle Security requirements Environmental analysis Incident / risk alerts Operational threats Failure analysis Misuse Cases Risk assessment Patch managementSystem analysis Architectures,System design components Security assessmentsVerification Test scenarios Design for security System test Security archi- Guidelines, standards ValidationSubsystem analysis tecture design Common criteria System integrationSubsystem designVerification Security review Penetration testsSW Analysis Subsystem testSW design Test driven Subsystem integrationVerification development ChecklistsSoftware- / Hardware SW- / HW- testImplementation and SW- / HW- integrationVerification Code analysis Security reviews © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 13
  • 14. Quality Requirements Engineering (QRE):Example: Security SystemsSecurity architecture and design Engineering  Develop security architecture on system level  Keep architecture as simple as possible  Adaptation of existing building blocks is difficultImplementation  Create and use proven software components  Use coding standards, guidelines  Employ tools for static analysis, fix compiler warning causes Consider quality requirements as a system property. Use different means to prevent critical defects.© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 14
  • 15. Quality Requirements Engineering (QRE):Example: Security Systems EngineeringSecurity verification:  Security reviews on all security-relevant artifacts  Tests and simulationsSecurity validation:  Validation tests (completeness, correctness) – can be handled in context of “normal” validation  Penetration tests (vulnerabilities) – high manual effort, requires specific expertise Strive for detection of potential weaknesses and insufficient implementation at the earliest possible point of time.© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 15
  • 16. Quality Requirements Engineering (QRE):Example: Security  Example: Simulation / test of a security protocol Systems Engineering Test Cases Security Protocol Test Results Design Specification Simulation / Test© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 16
  • 17. Quality Requirements Engineering (QRE):Example: Security Activity Benefit Processes Adapt mature development  Security engineering activities are known, processes to factor in scheduled, and executed within “normal” development. security engineering.  Security is not treated as add-on.  Synergies can be exploited. Elicit security requirements  Assets to be protected are clearly identified. in the beginning of the  Basis for realization of security. project.  Test cases for security validation can be deduced. Review or test every security  Identification of issues at the earliest possible time. relevant artifact, use analysis  Automated tools increase confidence and reduce effort. and test tools. Manage embedded security  Specific embedded security expertise available when necessary. competencies. Quality requirements engineering is deeply engrained in systematic requirements engineering© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 17
  • 18. Large-Scale Medical Device Projects Project Overview Several thousand single product requirements Several million lines of code Several hundred developers in 5+ locations worldwide Multi-fold clinical applicationsSource: H IM © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 18
  • 19. Case Study: Embed Quality RequirementsEngineering into an Existing RE process Selected Issues Solutions  Feature model  Difficult mapping of requirements to existing  Value-based ranking of platform QR • Identification of customer  Architecture Model value Mapping • Controlling architectural  Quality Tree complexity • NFRs difficult to defineSource: H IM © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 19
  • 20. Issue 1: Mapping of requirements to Platform – Solution “Feature Model” Highest Level Benefits:  Higher level abstraction of grouping of requirements into sellable units: From 5,000 product requirements to 800+ features(*) Source: Estimates from product managers (factor ~ 6)  Visual domain model for healthcare workflows (tree & graphical) Graphical View  Reduction of (de-) scoping effort by ~ 30% (*)  Reduction in time to understand aspects of the system  Hierarchical relationships enable mapping of stakeholder requests and visualize dependencies  Basis for introducing variability management Hierarchical View  Feeds the product backlog Source: H IM © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 20
  • 21. Issue 2: Identification of customer value –Solution “Forced Ranking” Characteristics:  Ranking is used to determine the release backlog  Main criteria for ranking are business value, technical risk and effort Benefits:  Only features with the highest business value (and feasibility) are implemented  Feature independence assures parallelization of development  Simulation of optimal release plan (what- if analysis)Source: H IM © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 21
  • 22. Issue 3: Controlling – Solution“Architecture Model Mapping” F Feature Model Characteristics:  Identifies links between features and their F F F implementation SWF SWF SWF SWF SWF SWF SWF  Explicit modeling of variability in the architecture S Architecture Model Benefits: SS SS SS  Architectural decisions motivated by features C C C C C C and product-line variability  Enable reduction of architectural complexity  Support impact analysis for (de-) scoping sessions  Early identification of architectural risks  Improved accuracy of early effort estimates  Reduction of number of scoping sessionsSource: H IM © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 22
  • 23. Issue 4: NFRs difficult to define forplatform – Solution “Quality Tree” Characteristics: Example Quality Tree - Extract  Quality requirements most challenging to define (subjective, domain-specific)  Quality Tree provides an effective means for collecting and prioritizing qualities  Analysis technique based on business drivers, key usage scenarios and international standards Benefits:  Identification of key architectural risks to consider Example: Learnability  Transparency of qualities‘ definition to all  Learning time of an educated physician stakeholders shall be less than x minutes ...  Explicit link of business drivers and platform architectureSource: H IM © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 23
  • 24. Contents  Goals  Brief Look on Siemens and Vector  Business and Environment  Quality Requirements Engineering  Results and Summary  Further Information© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 24
  • 25. Quality Requirements Engineering Impacts on Requirements Engineering Value orientation 1. Understand valuation of quality Global competition requirements Cost pressure 2. Consistently prioritize Shorter Life-Cycles 3. Address system context Reliability 4. Stay agile and lean Safety Resilience 5. Model quality requirements end- Serviceability to-end Complexity 6. Systematically build quality Auditability 7. Manage knowledge© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 25
  • 26. ResultsQuality Requirements Engineering Pays Off Improved system availability and reliability Ca. 30% Reduction of review effort due to early feature reviews vis-a-vis quality requirements Ca. 25% reduction of upfront requirement engineering work due to incremental requirements engineering Use of quality tree assures a clear focus on future customer needs and elimination of unnecessary redesigns© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 26
  • 27. Key Take-Aways Successful development of critical systems requires a business-driven requirements engineering approach with specific consideration of quality requirements A value-feature perspective for functional and quality requirements allows tracing business needs to implementation details Introducing a platform concept means to restructure quality requirements and link them to architecture components Continuous assessment and verification of business needs is necessary to judge priorities of quality requirements Consequent quality requirements engineering needs profound organizational change management to facilitate cross-cutting perspectives, innovative methodologies and collaboration© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 27
  • 28. Thank you for your attention! Copyright © Siemens AG 2011. All rights reserved.© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 28
  • 29. Contents  Goals  Brief Look on Siemens and Vector  Business and Environment  Quality Requirements Engineering  Results and Summary  Further Information© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 29
  • 30. Documented Experiences and Best Practicesfrom various Industry Projects English language: Software & Systems Requirements Engineering: In Practice 2009 McGrawHill German language: Systematisches Requirements Engineering Third edition, 2010 Dpunkt.verlagLink to web site McGrawHill Link to web site Dpunkt © 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 30
  • 31. Arnold Rudorfer Program Manager Platform Development Siemens Healthcare Diagnostics 62 Flanders Bartley Road Flanders, NJ, 07836 Phone: +1 973 927 28 28 Mobile: +1 609 954 23 84 Email: arnold.rudorfer@siemens.com© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 31
  • 32. Dr. Christof Ebert Managing Director Vector Consulting Services GmbH Ingersheimerstrasse 24 D-70499 Stuttgart Phone: +49 711 – 80670-175 Fax: +49 711 – 86070-444 Email: christof.ebert@vector.com© 2011 Siemens Healthcare Diagnostics Inc. Arnold Rudorfer, Siemens Healthcare Diagnostics, Christof Ebert, Vector Consulting Page 32