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Building Quality in Legacy Systems - The Art of Asking Questions, NDC Oslo 2020

Building Quality in Legacy Systems - The Art of Asking Questions, NDC Oslo 2020

The goal of being able to build quality in software products from the get-go is something that many organizations are trying to achieve. However, the very definition of software quality is somewhat elusive which makes it difficult to agree upon the perceived level of quality in software products. Moreover, working with legacy systems poses its own set of challenges as uncertainty of preserving overall quality in the legacy product seems to be an everyday struggle for many teams.
This talk builds on a multi-perspective definition suggested by Gojko Adzic in his blogpost “Redefining Software Quality” some years ago. For each perspective a series of well-defined questions will be presented that help teams challenge its own assumptions about quality in the end-product.

The talk is based on practical applications of Gojko’s definition as embraced by the teams working on a legacy enterprise software in healthcare domain.

Mufrid Krilic

June 12, 2020

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  1. E N A B L I N G E F

    F I C I E N T H E A L T H C A R E Mufrid Krilic Senior Software Developer/Coach DIPS AS, Norway @mufridk Building Quality In Legacy Systems – The Art of Asking Questions Her kan du legge inn bilde. Du finner figurer her: Link
  2. Gojko Adzic - Using Maslow as an Analogy for Defining

    Software Quality Blogpost: • «Redefining Software Quality» • https://gojko.net/2012/05/08/redefining-software-quality/
  3. Maslow - Physiological Needs • Quality methods: • TDD •

    Correct metrics: • Bug count • Code Coverage Roles to focus on: • Beta-users • Operations
  4. Maslow – Safety Needs • Quality methods: • Performance testing

    • Risk analysis • Architecture and design patterns Roles to focus on: • End-users • People working with information security
  5. Maslow – Love/Belonging Needs • Quality methods: • Usability testing

    • Design thinking • UX design Roles to focus on: • End-users
  6. Maslow – Esteem Needs • Quality methods: • Continuous delivery

    • DevOps • Correct metrics • Production environment measurements Roles to focus on: • End-users, Management
  7. Maslow – Self-actualization Needs • Quality methods: • Impact Mapping

    • Correct metrics • What impact did the software product make? • Did we make or save money? Roles to focus on: • Decision makers • Broader user community • Public relations
  8. Good enough – how to know where to invest? The

    more you invest in quality on this level the better Focus on good enough
  9. Different perspectives in the legacy system  Ask questions related

    to – Delivery process – Conditions of acceptance – Code and product maintainability – Security and performance – Domain-specific context in existing operational environments
  10. Delivery process related questions  Documentation  Any manual steps

    in the delivery process?  Compatibility with previously installed versions in production – Can multiple versions of the product exist side by side? Deployable?
  11. Conditions of Acceptance  Testing integration points with other parts

    of the system – What are my dependencies? – How to avoid introducing undesirable behavior? – Learn from experiences of the past – Talk to people in your organization   Invest in exploratory testing Functionally ok?
  12. Code and product maintainability related questions  Diagrams and maps

    – How to document integrations with other parts of the application?  Versioning – Consider releasing only parts of the legacy system if possible  Logging/Profiling – Do we have enough logging to be able to monitor usage in production? Functionally ok?
  13. Security and performance related questions  Performance testing  Memory

    leaks, memory footprint  Authentication, authorization, audit  Code analysis for discovering patterns that could lead to bugs in production – Asynchronous communication patterns – Multithreading issues Performant, secure?
  14. Domain-specific context in existing operational environments  How is the

    legacy system used today? – To what extent will users’ behavior change with new functionality?  Compatibility with specific configurations customers may have applied on-site  Consider constraints that may be imposed by customers’ organizational structure – Operational environment decisions • E.g. moving to data centers Usable? Useful? The most challenging questions to address
  15. Summary: Mapping of different perspectives to the software quality pyramid

    Conditions of acceptance Delivery process Code and product maintainability Security and performance Domain-specific context in existing operational environments
  16. The Consequence of Applying this Approach • Relentless learning •

    Strengthening the team’s ability in decision-making • Consequence is that every piece of work is bigger than initially assumed • Choose a set of questions that work for you at the time • Then gradually expand The Takeaway