Managing Software Debt. Continued Delivery of High Values as Systems Age

Transcription

1 Managing Software Debt Continued Delivery of High Values as Systems Age

2 Speaker - Chris Sterling Certified Scrum Trainer Managing Consultant, Agile Coach, and Architect at SolutionsIQ Consults on enterprise architecture and Agile software development practices across a spectrum of industries Founder of the International Association of Software Architects (IASA) Puget Sound chapter Supports Seattle Scrum Users Group with Kane Mar UW Extension Agile Developer Certification Program board member csterling@solutionsiq.com Blog: Delivering the best in Agile development, consulting, training and coaching services, SolutionsIQ offers a full range of technology services from Agile training and coaching to software delivery and talent acquisition. 2

3 The Problem Software gets more difficult to add features to as it ages Business expectations do not lessen as software ages Software must remain maintainable and changeable to meet needs of business over time Lack of emphasis on software quality attributes

4 Software Debt Creeps into our systems and leaves our organizations with software asset liabilities

5 Software Asset Liabilities Like-to-like migrations Limited experts capable to work on a system Long release stabilization periods Increasing duration of costly regression test phases Higher costs for people to work on legacy software

6 Like-to-Like Migrations It will be easy since we worked on the original version - although we understand the domain we will be fighting with new features, technology, tools, and processes We don t have any other options - Refactoring and test automation are potential alternatives to like-to-like migrations.

7 Limited Expertise Risk increase as expertise becomes more limited for an aging software system.

8 Long Stabilization Periods Release 1 Release 2 Release 3 30% 70% 45% 55% 60% 40% Feature Development - Business Value Stabilization Period - Cost of Delay

9 Costly Regression Test Phases Cost of Feature Implementation $5,000 $3,750 $2,500 $1,250 $ Weeks Test-Driven Development and Continuous Integration Manual Regression Test Execution

10 Higher Costs for People Legacy software expenses increase with time COBOL programmers more expensive due to less experienced people to meet demand Specialized tools have more of a cult following with higher bill rates

11 Software Debt Creeps In Function Area Component 1 Component 2 Component 3 F F F F F

12 Software Debt Creeps In Function Area Component 1 Component 2 Component 3 Component 4 F F F F F F F F F F

13 Software Debt Creeps In Function Area Component 1 Component 2 Component 3 Component 4 Component 5 F F F F F F F F F F F F

14 Types of Software Debt Technical Debt Quality Debt Configuration Management Debt Design Debt Platform Experience Debt

15 Technical Debt Issues in software implementation that will impede future development if left unresolved

16 * Technical Debt Technical Debt includes those internal things that you choose not to do now, but which will impede future development if left undone. This includes deferred refactoring. Technical Debt doesn t include deferred functionality, except possibly in edge cases where delivered functionality is good enough for the customer, but doesn t satisfy some standard (e.g., a UI element that isn t fully compliant with some UI standard). * Ward Cunningham - Technical Debt -

17 Quality Debt A lack of quality, either technical or functional, will minimize value per feature added increasingly over time

18 $40,000 $30,000 $20,000 $10,000 $0 Release 1 Release 2 Total Debt Accrued Accrual of Software Debt Debt compounds over time

19 Sprints Bugs Fixed Debt Accrued (Bugs) Break/Fix Only Prolongs It Longer cycle times to fix bugs increases debt in surrounding code

20 A Fit Case Study Cost reduction using Fit for test automation and data conversion

21 Background Testing was taking 75 person hours during 2 full test runs consisting of: Comprehensive manual regression testing Data conversion and validation Cost for testing was $17,000 each iteration

22 Introducing Fit into Testing Process After 8 iterations team had introduced healthy amount of Fit fixtures and automated tests Reduced 70+ hour test runtime down to 6 hours which now included: Fit automated regression testing Data conversion and validation automated with Fit fixtures Reduced cost of testing each iteration from $17,000 to $7,000

23 Bug or Enhancement? In Bug Tracking System In Product Backlog

24 The Situation: Bug Came from important customer and must be fixed and deployed within 2 weeks

25 The Situation: Enhancement Must be in next release which is 1 month away and takes multiple user stories currently estimated as 3 weeks

26 The Situation: Should we work on bugs or enhancements first?

27 Maintain One List of Work Put all work into Product Backlog Make tradeoff decisions based on reality of the situation

28 Configuration Management Debt Debt in this area can be unpredictable, prone to error, and cause poor decision-making on quality attributes of a system

29 Traditional Source Control Management

30 Traditional Source Control Management Main Branch

31 Traditional Source Control Management Version 1 Branch Code Complete Integrate for Version 2 Main Branch

32 Traditional Source Control Management Version 1 Branch Code Complete Integrate for Version 2 Debt Main Branch Death March

33 Traditional Source Control Management Version 1 Branch Code Complete Integrate for Version 2 Debt Main Branch Death March { Debt accrues quickly within stabilization periods

34 Flexible Source Control Management

35 Flexible Source Control Management Main Branch

36 Flexible Source Control Management Version 1 Main Branch

37 Flexible Source Control Management Version 1 Version 2 Main Branch

38 Flexible Source Control Management Version 1 Version 2 Main Branch { Not Easy! Must have proper infrastructure to do this.

39 Continuous Integration Each Team Member Checks in Product Artifacts to Source Control Every Day

40 Scaling to Multiple Integrations

41 Design Debt Design decays when not attended to so put effort into maintaining your software by designing all the time

42 Merciless Refactoring Refactoring: a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior.* Merciless: having or showing no [mercy - showing great kindness toward the distressed] Relieve your distressed code through kindness and disciplined restructuring * From

43 Automate Testing to Support Refactoring Refactoring cannot be done effectively without automated tests surrounding code Start by creating automated test which fails If difficult to create at unit level look at automated acceptance tests from functional perspective Over time look for ways to create automated unit tests

44 Proper Architecture Design Provides Value Software is a business asset and our job is to produce the greatest Return on Investment (ROI) by delivering high value quickly

45 * Architecture Risk Themes Observed that twice as many risk themes are risks of omission as are risks of commission. That is, risk themes identify decisions or investigations that were never made rather than those that were made and could lead to undesirable consequences. No discernible relationship between articulated business and mission goals of a system and risk themes from an ATAM evaluation of that system No discernible relationship between domain of system being evaluated and risk themes associated with development of that system * From Risk Themes Discovered Through Architecture Evaluations by Len Bass, Robert Nord, William Wood, and David Zubrow

46 * Abuse User Stories Implement Security for User Information * From User Stories Applied presented by Mike Cohn Agile 2006

47 * Abuse User Stories Implement Security for User Information As a Malicious Hacker I want to steal credit card information so that I can make fraudulent charges * From User Stories Applied presented by Mike Cohn Agile 2006

48 Platform Experience Debt How many of you are writing Legacy Code?

49 How to Combat Platform Experience Debt Ignore it (I do not suggest this!) Make interface to underlying system Transfer learning of platform to more people Rewrite system on more current platform Slice functionality to more current platform over time

50 Architecture Team Patterns Virtual Architect Pattern Integration Team Pattern Component Shepherd Pattern Team Architect Pattern

51 Enterprise Planning Virtual Architect Pattern

52 Virtual Architect Pattern Pros Share architecture ideas and needs across teams Based on verbal communication Cons Usually singles out special Team Member role Could lead to top-down architecture decisions IT may gain extensive influence and begin to run Product Backlog prioritization for architecture needs

53 Integrate Features All features are implemented and integrated Feature Development Integration Team Pattern

54 Integration Team Pattern Pros Reduces complexity on Feature Teams Forces delivery from Integration Team instead of interface and deployment designs Cons Perpetuates specialized roles Don t always work on highest value Product Backlog items

55 Component Shepherd Pattern

56 Component Shepherd Pattern Pros Share more knowledge within organization to minimize platform experience debt Work on highest value Product Backlog items Cons Not always optimal as using individual knowledge Difficult to learn multiple systems across Teams

57 Team Architect Pattern Whole Team leads architecture decisions

58 Team Architect Pattern Pros Team owns architecture decisions Decisions are made close to implementation concerns Cons May not have appropriate experience on Team Team could get stuck on architecture decisions

59 Lets wrap this up...

60 Principles for Managing Software Debt Maintain one list of work Emphasize quality Evolve tools and infrastructure continually Improve system design always Share knowledge across the organization And most importantly, hire great people to work on your software!

61 Principles of Agile Software Quality The system always runs No code is written without a failing test Zero post-iteration bugs * From Flawless Iterations presented by Alex Pukinskis at Agile 2005

62 Continuous Integration Each Team Member Checks in Product Artifacts to Source Control Every Day

63 Thank you Questions and Answers

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