Optimizing Inspection Practices: Perspective-Based Approach for NASA IV&V

1. OSMA SAS 08Infusion of Perspective-Based Inspections forNASA IV&V(Executive Briefing) Dr. Forrest Shull, FCMD Kurt Woodham, L-3 Communications MAC-T IVV-08-153

2. Perspective-Based Inspection (PBI) • A procedural technique incorporating three best practices: • Giving each reviewer a particular and unique focus (or perspective) on the document under review • Base perspectives on document stakeholders to help understand necessary participants, relate inspection tasks to development skills • Making individual review of a document an active (rather than passive) undertaking • Articulating the quality aspects of interest • Uses defect analysis (e.g. from bug trackers, configuration management systems, previous inspection, or test results) as one input on which to customize a solution MAC-T IVV-08-153

3. Perspective-Based Inspection (PBI) • History • 2001-2003: SARP research funding • Refined basic approach, implemented on NASA projects and in classrooms, measured results • 2004: Tech infusion with Flight Software Branch / GSFC • Goal: Produce new Branch standards • Success metric: Based on experiences on pilot(s), how much of the recommended process is adopted by Branch? • 2004: Tech infusion with United Space Alliance / JSC • Goal: Reduce defect slippage over current increment • Success metric: Show reduced defect slippage on PB-inspected artifacts • 2007-2009: SARP funding for improved general inspection planning • Other Results and Benefits • Improved defect detection effectiveness substantially (NASA & elsewhere) • Helped re-invigorate inspection practices • Forms the basis of industrial and academic training MAC-T IVV-08-153

4. Adopting PBI for IV&V • Tailoring required for new domain, new issues, new artifacts Requirements Specifications System reference model PB Inspection PB Inspection Requirements defects Model defects MAC-T IVV-08-153

5. Adopting PBI for IV&V: Tailoring Process • Understand team-specific quality concerns • Understand likely perspectives for the team • Refine set of perspectives and define procedures for each. E.g., • What quality concerns map to which perspectives • What is a feasible/effective process for checking those concerns • Finalize procedures and provide training • Analyze ongoing inspection results (and update procedures if necessary) • Monitor downstream defect profile • Write final report Status: Reviewed sample models & processes; Constructed draft PBI techniques; Created draft training course MAC-T IVV-08-153

6. Adopting PBI for IV&V • Initial perspectives for this domain: • Modeler • Uses requirements & existing models to create the next iteration • Quality foci: Appropriate level of detail in requirements; completeness and clarity of requirements & models; consistency and correctness of models • Domain expert • Assesses whether model accurately and usefully captures domain • Quality foci: Correctness of requirements (independent of models); identification of stakeholders and evaluation of usability from their POV; checking flow of control & use of reusable components • Quality assurance • Assesses whether models and system can be validated properly • Quality foci: Handling of exception cases / unexpected system conditions; robustness of system; testability MAC-T IVV-08-153

7. Path Forward • Validate & refine PBI instantiation via interviews • Check perspectives and associated scenarios with key stakeholders • Flesh out detailed approaches for each perspective with respect to each defect category • Application • In context of IV&V of JWST • Training course material delivered and training will be executed near-term • Technology provider will facilitate initial inspections, and will be on-call during subsequent inspections • Evaluation • Success metric: Effectiveness of PB inspection in comparison to past inspections MAC-T IVV-08-153

8. Contact information Forrest Shull fshull@fc-md.umd.edu 301-403-8970 Kurt Woodham Kurt.Woodham@L-3com.com 757-644-5807 MAC-T IVV-08-153