1 / 44

Hany H. Ammar

بسم الله الرحمن الرحيم الحمد لله ، والصلاة والسلام على رسول الله. Introduction to Risk Management And Software Architecture Risk Assessment. Hany H. Ammar LANE Department of Computer Science and Electrical Engineering West Virginia University, Morgantown, West Virginia, USA, and

terin
Télécharger la présentation

Hany H. Ammar

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. بسم الله الرحمن الرحيم الحمد لله ، والصلاة والسلام على رسول الله Introduction to Risk Management And Software Architecture Risk Assessment Hany H. Ammar LANE Department of Computer Science and Electrical EngineeringWest Virginia University, Morgantown, West Virginia, USA, and Faculty of Computers and Information, Cairo University, Cairo, Egypt

  2. OUTLINE • Risk Management • Software Architecture Risk Assessment • Maintainability-based risk • Conclusions • Next Steps SW Architecture Risk Assessment Keynote Presentation MySEC’06

  3. Risk Management SW Architecture Risk Assessment Keynote Presentation MySEC’06

  4. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  5. For NASA Programs • RISK MANAGEMENT: An organized, systematic decision-making process that efficiently identifies risks, assesses or analyzes risks, and effectively reduces or eliminates risks to achieving program goals. • RISK: A Program “Risk” is any circumstance or situation that poses a threat to: crew or vehicle safety, Program controlled cost; Program controlled schedule; or major mission objectives, and for which an acceptable resolution is deemed unlikely without a focused management effort SW Architecture Risk Assessment Keynote Presentation MySEC’06

  6. Risk Management Cycle • Identify: Identify that a risk exits and give it a meaningful name. • Analyze: Determine the severity of the risk according to the risk matrix. If the risk is negligible (low to medium severity, low likelihood of occurrence), stop here. However, if the risk could cause damage to the system or the system's users, continue. • Plan: Decide how to combat the risk based on the risk's severity and likelihood of occurrence. • Mitigate: Follow the plan formulated in the previous phase as closely as possible to combat the risk. If this approach does not work, return to the previous phase and make a new plan. If the plan does work, continue analyzing the risk to determine whether it has been reduced to an acceptable severity level. • Track: Once the risk has been mitigated to an acceptable severity level, the risk should be tracked to ensure the continued control of the risk. If at any time the risk seems to resurface, the risk management cycle should begin again, starting with the analysis phase. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  7. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  8. Risk Definition • According to NASA Software Safety Technical Standard, risk is defined as: “exposure to the chance of injury or loss. It is a function of the possible frequency of occurrence of the undesired event, of the potential severity of resulting consequences, and of the uncertainties associated with the frequency and severity”. • For software intensive systems, a risk is a combination of a likelihood of occurrence of an abnormal event or failure and the potential consequences or severity of that event or failure to a system's operators, users, or environment SW Architecture Risk Assessment Keynote Presentation MySEC’06

  9. Risk Matrix SW Architecture Risk Assessment Keynote Presentation MySEC’06

  10. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  11. NASA IV&V Facility NPD 2820.1C for Software IV&V Policy states:"Task the IV&V Facility in Fairmont, West Virginia to manage the performance of all IV&V for software identified per the established criteria, and for any other safety critical software (as defined in NASA-STD-8719.13)" SW Architecture Risk Assessment Keynote Presentation MySEC’06

  12. IV&V Function • Software Independent Verification & Validation (IV&V) is a systems engineering process employing rigorous methodologies for evaluating the correctness and quality of the software product throughout the software life cycle. • Software IV&Vis adapted to the characteristicsof the project. Different projects require different level of IV&V SW Architecture Risk Assessment Keynote Presentation MySEC’06

  13. IV&V Lifecycle Activities Mission Readiness Review System Retirement System Requirements Review Preliminary Design Review System Test Critical Design Review S/W FQT Launch Initial IVVP Signed Baseline IVVP Signed • - IV&V provides support and reports for Project milestones • Technical Analysis Reports document major phases • IVVP is updated to match changes in Project IV&V Provides CoFR IV&V Final Report Concept Phase 2.0 Requirements Phase 3.0 Design Phase 4.0 Implementation Phase 5.0 Test Phase 6.0 Operations & Maintenance Phase 7.0 IV&V Phase Independent Support 1.0 Note: numbers correspond to IV&V WBS • Life-cycle IV&V is designed to mesh with the Project schedule and provide timely inputs to mitigate risk • Dialog between the IV&V Facility and the Project must begin before SRR • For most Projects, IV&V ends (and the Final Report is delivered) on or about MRR. Some Projects have extended S/W development post-launch or major upgrades/maintenance (e.g. Shuttle, MER) SW Architecture Risk Assessment Keynote Presentation MySEC’06

  14. Software Project Resolution Project Resolution is commonly categorized into three resolution types: • Successful Projects • Completed and operational, and: • On Schedule • On Cost • With all originally specified features and functions • Challenged Projects • Completed and operational, but: • Behind Schedule------- Project Risk • Over Cost--------------- Project Risk • With fewer features and functions than originally specified ------------ Product Risk • Failed Projects: • Cancelled before completion or never implemented SW Architecture Risk Assessment Keynote Presentation MySEC’06

  15. Software CHAOS The Standish Group has examined 30,000 Software Projects in the US since 1994. This "CHAOS" research has revealed a decided improvement in IT project management with the implementation of standards and practices such as IV&V. This improvement correlates with the rise in project success depicted in the chart below: Project Resolution History (1994-2000) The Standish Group International, Inc.: Extreme CHAOS (2001) - The 2001 update to the CHAOS report. http://www.standishgroup.com/sample_research/PDFpages/extreme_chaos.pdf SW Architecture Risk Assessment Keynote Presentation MySEC’06

  16. Error Detection/Correction Early error detection and correction are vital. The cost to correct software errors multiplies during the software development lifecycle. Early error detection and correction reduce costs and save time. Direct Return on Investment of Software Independent Verification and Validation: Methodology and Initial Case Studies, James B. Dabney and Gary Barber, Assurance Technology Symposium, 5 June 2003. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  17. IV&V Characteristics • Includes Risk Identification and Mitigation Techniques • Provides Independent Evaluation / Assessment of: • Are we building the product right? = Verification • Are we building the right product? = Validation • Requires Technical, Managerial and Financial Independence • Makes a value added contribution, everyone shares the same mission success objective • For NASA Management - Provides Mission Assurance • For Project Management - Provides Unbiased Source of Help • Helps deliver • Risk Identification and Mitigation • Increased Quality and Safety • Improved Timeliness and Reliability • Reduced Rework Cost NPD 8730.4: Requires NASA programs and projects that contain mission or safety critical software to document decisions concerning the use of IV&V. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  18. OUTLINE • Risk Management • Software Architecture Risk Assessment • Reliability-based risk • Performance-based risk • Maintainability-based risk • Component Ranking • Conclusions • Next Steps SW Architecture Risk Assessment Keynote Presentation MySEC’06

  19. Software Architecture Risk Assessment This work is funded in part by grants to West Virginia University Research Corp. from the NSF (ITR) Program, and from the NASA Office of Safety and Mission Assurance (OSMA) Software Assurance Research Program (SARP) managed through the NASA Independent Verification and Validation (IV&V) Facility, Fairmont SW Architecture Risk Assessment Keynote Presentation MySEC’06

  20. Project Overview • Risk Assessment of software architecture components, usage scenarios, and requirements • Risk definition is based on * Frequency of abnormal events * Severity or consequences of events • Reliability-based risk, • Performance-based risk • Requirement–based risk • Severity Analysis • Maintainability-based risk What keeps satellites working 24/7 ? SW Architecture Risk Assessment Keynote Presentation MySEC’06

  21. Software Architecture Risk Assessment • An architecture-based approach for risk assessment • Components\connectors, requirements, and scenario risk, • Define several types of risk factors • Reliability-based Risk [IEEE Trans. on Rel 2001, on SE, 2002, 2003] • Probabilityof failure • * Severity or Consequences of this failure • Maintainability-based Risk [RAMS 06, ICSM 05, ICSM 04] • Probability of performing maintenance task • * Cost of performing this task • The losses caused by low system maintainability can be: • High cost of maintenance effort • Loss of the system by aging • Performance-based Risk [IEEE Trans. SE, Jan. 2005] • Probabilityof missing timing or performance requirements • * Severity or Consequences SW Architecture Risk Assessment Keynote Presentation MySEC’06

  22. Components Risk Risk Factor Components Importance / Benefits • Identify the high risk components of the system in terms of Reliability/Maintainability/Performance SW Architecture Risk Assessment Keynote Presentation MySEC’06

  23. Software Architecture Risk Assessment Reliability-based Risk Analysis Maintainability-based Risk Analysis Performance-based Risk Analysis Software Architecture Risk Assessment Methodology Requirements Model System Architecture Model Components Ranking Components Risk Factors SW Architecture Risk Assessment Keynote Presentation MySEC’06

  24. OUTLINE • Risk Management • Software Architectures • Software Architecture Risk Assessment • Maintainability-based risk • Conclusions • Next Steps SW Architecture Risk Assessment Keynote Presentation MySEC’06

  25. Maintainability-based Risk [ICSM 05] AbdelMoez, Goseva, Ammar, Mili, Fuhrman, “Architectural level Maintainability Based Risk Assessment” [RAMS 06] AbdelMoez, Goseva, Ammar,” Methodology for Maintainability Based Risk Assessment”, Jan 2006. SW Architecture Risk Assessment Keynote Presentation MySEC’06

  26. Importance / BenefitsMaintainability-based Risk • According to Pigoski, 60%-80% of the system budget is spent on maintenance • Enhancements (perfective/ adaptive maintenance) account for 78%-83% of the maintainer effort SW Architecture Risk Assessment Keynote Presentation MySEC’06

  27. Importance / BenefitsMaintainability-based Risk • Unisys holds the NASA contract to maintain and support 14 million lines of ground software for the space shuttle • There were 3,800 requirement changes made to the software after the loss of Challenger. These changes resulted in 900 software releases, of which 30 applied to the mission-control center with 3 of these being major upgrades • Reference: • IEEE Software, Vol.6,  No.1,  pp. 116-119 http://hebb.cis.uoguelph.ca/~dave/343/Lectures/introduction.html SW Architecture Risk Assessment Keynote Presentation MySEC’06

  28. Importance / BenefitsTrade off Analysis for Perfective Maintenance Risk Factor Components Risk Components Patterns Maintainability risk for perfective maintenance (open source case study Borg) SW Architecture Risk Assessment Keynote Presentation MySEC’06

  29. Software Architecture Risk Assessment Methodology:Maintainability-based Risk SW Architecture Requirments maturity Index / change / error reports (1) Estimate components Initial Change Probability (ICP) (3) Estimate Size of Change (SC) (2) Estimate Change Propagation (CP) probabilities ICP=[icpi] SC=[sci/j] CP=[cpi/j] (4) Estimate component risk factor SW Architecture Risk Assessment Keynote Presentation MySEC’06

  30. Maintenance change propagation Outgoingmaintenance Incoming maintenance SW Architecture Risk Assessment Keynote Presentation MySEC’06

  31. . . V13 Required Services cpij = Estimating Change Propagation V1 C2 C1 = 1 V11 V12 V13 Change in Provided Service Change = 0 • Change Propagation Probabilities matrix CP=[cpij] • cpijis the probability that a change inCidue to corrective/ perfective maintenance requires a change inCjwhile maintaining the overall function of a system S • cpij = P([Cj]  [Cj'] | [Ci]  [Ci'] ^ [S] = [S'] ) • cpijis estimated by SW Architecture Risk Assessment Keynote Presentation MySEC’06

  32. V1 C2 C1 V11 V12 M1 M2 M3 … M7 V13 Receiving Component methods Change in Provided Service Change scij = Estimating Size of Change • Size of changeSC=[scij ] scijis definedas the ratio between the number of affected methods of the receiving component caused by the changes in the interface elements of the providing components and the total number of methods in the receiving component • scijis estimated by SW Architecture Risk Assessment Keynote Presentation MySEC’06

  33. CM1 Maintainability-Based Risk in Adaptive Maintenance Context SW Architecture Risk Assessment Keynote Presentation MySEC’06

  34. Case Study: NASA CM1 UML Model Structure Diagram • The UML-RT Model of CM1 was • Developed by WVU students (Nathan, Tom and Rajesh, Summer 2004) based on the CM1 software design specification SW Architecture Risk Assessment Keynote Presentation MySEC’06

  35. Change Propagation Probabilities for CM1 • The Change Propagation probabilities CP is estimated using the CM1 UML model • The Change Propagation probabilities CP can be automatically estimated from UML-RT models, or java source SW Architecture Risk Assessment Keynote Presentation MySEC’06

  36. Size of Change for CM1 • The Size of Change metrics SC is estimated using the CM1 UML model • The Size of Change metrics SC Probabilities CP can be automatically estimated from UML-RT models, or Java source SW Architecture Risk Assessment Keynote Presentation MySEC’06

  37. Software Architecture Risk Assessment Methodology:Maintainability-based Risk SW Architecture Requirments maturity Index / change / error reports (1) Estimate components Initial Change Probability (ICP) (3) Estimate Size of Change (SC) (2) Estimate Change Propagation (CP) probabilities ICP=[icpi] SC=[sci/j] CP=[cpi/j] (4) Estimate component risk factor SW Architecture Risk Assessment Keynote Presentation MySEC’06

  38. Maintainability-based Risk For corrective maintenance (case study CM1) ICP is estimated using error reports data SW Architecture Risk Assessment Keynote Presentation MySEC’06

  39. Components BIT CCM DCI DCX DPA EDAC ICUI 1553 SCUI SSI TIS TMALI Severity Level Minor Cat. Cat. Minor Major Major Critical Cat. Critical Cat Major Critical Prioritizing Corrective Maintenance Tasks for CM1 SW Architecture Risk Assessment Keynote Presentation MySEC’06

  40. Maintainability-based Risk Maintainability risk for Adaptive maintenance (case study CM1) ICP is estimated using change reports data SW Architecture Risk Assessment Keynote Presentation MySEC’06

  41. Tool Support SW Architecture Risk Assessment Keynote Presentation MySEC’06

  42. Technology Readiness Level The Software Architecture Risk Assessment Tool Support SW Architecture Risk Assessment Keynote Presentation MySEC’06

  43. Conclusions • Risk Management is vital to the success of projects and products • A risk Assessment process is needed • Software Architecture is a major determinant of software quality • Software Architecture can be used to manage project and product risks • Development of a methodology and a process for software architecture risk assessment • Continued development of a software architecture risk assessment tool to support the methodology SW Architecture Risk Assessment Keynote Presentation MySEC’06

  44. Papers Published • Vittorio Cortellessa, Katerina Goseva-Popstojanova, Kalaivani Appukkutty, Ajith R. Guedem, Ahmed Hassan, Rania Elnaggar, Walid Abdelmoez, Hany H. Ammar, “Model-Based Performance Risk Analysis, IEEE Transactions on Software Engineering, January 2005, (Vol. 31, No. 1), pp.3-20. • Katerina Goseva-Popstojanova, Ahmed Hassan, Ajith Guedem, Walid Abdelmoez, Diaa Eldin M. Nassar, Hany Ammar, Ali Mili, "Architectural-Level Risk Analysis Using UML", IEEE Transactions on Software Engineering, October 2003 (Vol. 29, No. 10), pp.946-960. • S. Yacoub, H. Ammar, “A Methodology for Architectural-Level Reliability Risk Analysis,” IEEE Transactions on Software Engineering, Vol. 28, No. 6, June 2002. • W. AbdelMoez, K. Goseva-Popstojanova, H.H. Ammar,” Methodology for Maintainability-Based Risk Assessment”, Proc. of the 52nd Annual Reliability & Maintainability Symposium(RAMS 2006), Newport Beach, Ca., January 23-26, 2006. • Israr P. Shaik , W. Abdelmoez, R. Gunnalan, M. Shereshevsky, A. Zeid, H.H. Ammar, A. Mili, C. Fuhrman, “Change Propagation for Assessing Design Quality of Software Architectures”, Proc. of 5th IEEE/IFIP Working Conference on Software Architecture (WICSA), Pittsburgh, Pa., USA, November 6-9, 2005. • AbdelMoez, W., I. Shaik, R. Gunnalan, M. Shereshevsky, K. Goseva-Popstojanova, H.H. Ammar, A. Mili, C. Fuhrman, “Architectural level Maintainability Based Risk Assessment”, Proc. of poster papers in IEEE International Conference on Software Maintenance (ICSM 2005), Budapest, Hungary, September 25-30,2005. • W. Abdelmoez, D. M. Nassar, M. Shereshevsky, N. Gradetsky, R. Gunnalanm and H. H. Ammar, Bo Yu, and Ali Mili "Error Propagation in Software Architectures". In Proceedings of the 10th International Symposium on Software Metrics (METRICS'04), September 11 - 17, 2004 , IEEE Comp. Soc., pp 384-393 • Abdelmoez, W., M. Shereshevsky, R. Gunnalan, H. H. Ammar, Bo Yu, S. Bogazzi, M. Korkmaz, A. Mili, "Software Architectures Change Propagation Tool (SACPT),” 20th IEEE International Conference on Software Maintenance (ICSM'04)September 11 - 14, 2004 , Chicago, Illinois, IEEE Comp. Soc., pp 517 • A. Hassan, K. Goseva-Popstojanova, and H. Ammar, “UML Based Severity Analysis Methodology”, Proceedings of the 2005 Annual Reliability and Maintainability Symposium (RAMS 2005), Alexandria, VA, January 2005. SW Architecture Risk Assessment Keynote Presentation MySEC’06

More Related