user-centered system design agile - uppsala university · • ”backlog” of requirements,...
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Department of Information Technology Uppsala university
User-centeredSystem Design Agile
Uppsala university
2009-02-24 | #2@ UU/IT
Business modeling Requirements Analysis & design Implementation
Test Deployment Configuration & Change Management:
Overview
Project Management Environment
Usability Design
Methods - what are they? Why do we have them?
Uppsala university
2009-02-24 | #3@ UU/IT
Failed IT projects
28
26
27
16
23
28
40
31
49
46
33
53
0% 20% 40% 60% 80% 100%
2000
1998
1996
1994
SuccessCancelledPartly failed
Uppsala university
2009-02-24 | #4@ UU/IT
Why failed projects?Reasons?• Low usability
Not able to produce a good enough system?• Never delivered, or late
Not enough pressure/skill?• Missing functionality, or wrong functions
Not knowing what to do?
Uppsala university
2009-02-24 | #5@ UU/IT
The selling game
Analysis: needs
Req.
Contract
Analysis:time & money
Customer Developer
Uppsala university
2009-02-24 | #6@ UU/IT
Agile: everything on this page is wrong
“Requirements engineering (RE) is receiving increasing attention as it is generally acknowledged that the early stages of the system development life cycle are crucial to the successful development and subsequent deployment and ongoing evolution of the system. As computer systems play increasingly important roles in organizations, it seems there is a need to pay more attention to the early stages of requirements engineering itself (e.g., [6]).”Towards Modelling and Reasoning Support for Early-Phase RequirementsEngineering, Eric S. K. Yu, paper 1 for Neil
Uppsala university
2009-02-24 | #7@ UU/IT
Learing from the bestWhat is a successful system?Why is the reason it is good do you think?• Was this planned or by chance?
Uppsala university
2009-02-24 | #8@ UU/IT
Are we A or B?Q
ualit
y
Functionality
Qua
lity
Functionality
A B
Uppsala university
2009-02-24 | #9@ UU/IT
AgileA reaction against the ”heavy” methods and failed projects• Too little feedback• Too much method• Too large systems• Too many functions• No one likes these methods• The methods don’t deliver, they fail
Overall idea: • Minimize risk by developing software in short
amounts of time.
Uppsala university
2009-02-24 | #10@ UU/IT
AgileMain Entry: ag·ilePronunciation: 'a-j&l, -"jI(-&)lFunction: adjectiveEtymology: Middle French, from Latin agilis,from agere to drive, act 1 : marked by ready ability to move with quick easy grace <an agile dancer>2 : having a quick resourceful and adaptable character <an agile mind> - ag·ile·ly /-j&(l)-lE, -"jI(l)-lE/ adverb
Uppsala university
2009-02-24 | #11@ UU/IT
Key principlesWe cannot do as before. A change is needed.• Individuals and interaction over processes and
tools • Working software over comprehensive
documentation • Customer collaboration over contract
negotiation • Responding to change over following a plan
• http://agilemanifesto.org/
Uppsala university
2009-02-24 | #12@ UU/IT
Agile Manifesto Principles, 1Our highest priority is to satisfy the customer through early and continuous delivery of valuable software. Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage. Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale. Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done. The most efficient and effective method of conveying information to and within a development team is face-to-faceconversation.
Uppsala university
2009-02-24 | #13@ UU/IT
Agile Manifesto Principles, 2Working software is the primary measure of progress. Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely. Continuous attention to technical excellence and good design enhances agility. Simplicity-the art of maximizing the amount of work not done-is essential. The best architectures, requirements, and designs emerge from self-organizing teams. At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly.
Uppsala university
2009-02-24 | #14@ UU/IT
Is this a development process?
Uppsala university
2009-02-24 | #15@ UU/IT
Also a tool"Make sure there are whiteboards and coffee corners all over the building.” (IBM)
Uppsala university
2009-02-24 | #16@ UU/IT
What is Agile development?Framework, of values and principles
DSDM (Stapledon)
eXtremeProgramming
(Beck)Crystal (Cockburn)
AdaptiveSoftwareDevelopment(Highsmith)
FDD
Scrum
AgileModeling (Ambler)
Uppsala university
2009-02-24 | #17@ UU/IT
ScrumKen Schwaber in Financial Times: Scrum is different, he says, as it "takes people out of cubicles and puts them in a room with whiteboards.”
http://www.controlchaos.com/module/FT.php
Observation• SW development can be very different, in different places
Uppsala university
2009-02-24 | #18@ UU/IT
ScrumTakeuchi and Nonaka, 1986The paper that started it all:• The new new product development game• http://apln-richmond.pbwiki.com/f/New%20New%20Prod%20Devel%20Game.pdf
”The rules of the game in new product development are changing. Many companies have discovered that it takes more than the accepted basics of high quality, low cost, and differentiation to excel in today's competitive market. It also takes speed and flexibility.”
Uppsala university
2009-02-24 | #19@ UU/IT
Characteristics of ScrumObservation: • Using small, cross-functional teams historically
produces the best results Based on a rugby metaphor…• A Scrum Master acts as project manager/buffer
to the outside world• Product Owner, represents stakeholders• Team, developers (less than 10)
Uppsala university
2009-02-24 | #20@ UU/IT
Scrum actionsSprint, 30-day iteration• ”backlog” of requirements, decided at the scrum
Managed by Product OwnerDaily meeting, called a ”scrum”• Starts precisely on time with team-decided punishments if late• Only "pigs" may speak (pigs and chickens)• The meeting is time boxed at 15 minutes; all attendees stand
up• The meeting should happen at the same location and same
time every dayAll pigs say:1. What have you done since yesterday? 2. What are you planning to do by tomorrow? 3. Do you have any problems preventing you from
accomplishing your goal?
Uppsala university
2009-02-24 | #21@ UU/IT
SprintA Product Owner compiles all the changes planned for the product and prioritizes the possible functionalities.The result of the Product Owner’s work is a Product Backlog – a to-do list that is constantly reprioritized. Before each Sprint, the highest prioritized goals are transferred to a Sprint Backlog.Together with a user, the project members form a Scrum Team consisting of 5–9 people. During discussions with the Product Owner, the goal of the Sprint is determined and the prioritized functionality is broken down into detailed tasks. The team is self-organized and the members have a joint responsibility for the results.The Scrum Master coaches the development team, removes any possible impediments and constantly works to ensure that the team has the best possible circumstances for realizing the goals fixed for the Sprint.
Uppsala university
2009-02-24 | #22@ UU/IT
http://www.softhouse.se/Uploades/Scrum_eng_webb.pdf
Uppsala university
2009-02-24 | #23@ UU/IT
ReadingScrum in 5 minutes• http://www.softhouse.se/Uploades/Scrum_eng_webb.pdf
Ken Schwaber, co-developed the Agile process, Scrum. Video from Google Tech Talks: • http://video.google.com/videoplay?docid=-7230144396191025011
Uppsala university
2009-02-24 | #24@ UU/IT
At the same time…OOP is different from traditional procedural programmingThe business requirements were changing• Time-to-market important• Design-driven market• Need to show progress• Short product life expected
OOP-people see the successful patterns in problems like this
Uppsala university
2009-02-24 | #25@ UU/IT
XPKent Beck (1996/2000)A heavyweight methodology has many rules, practices, and documents. It requires discipline and time to follow correctly. A lightweight methodology has only a few rules and practices or ones which are easy to follow.
Uppsala university
2009-02-24 | #26@ UU/IT
Extreme ProgrammingA deliberate and disciplined approach to software developmentTo be more agile than traditional methodsCreate better software• Stresses customer satisfaction
Emphasizes team work
Uppsala university
2009-02-24 | #27@ UU/IT
Main aim of XP is to reduce the cost of change
Cos
t
Time
Then
Now
Uppsala university
2009-02-24 | #28@ UU/IT
5 values of XPCommunicationSimplicityFeedbackCourageRespect
Uppsala university
2009-02-24 | #29@ UU/IT
Communication tools?
Richness of communication channel
Com
mun
icat
ion
Effe
ctiv
enes
s
2 people atwhiteboard
2 people on phone
2 peopleon email
Videotape
Paper
Uppsala university
2009-02-24 | #30@ UU/IT
CommunicationAll communication must be rapid • No formal documentation
Frequent communication• One single room for all
Small note paper• Small design
Uppsala university
2009-02-24 | #31@ UU/IT
SimplicityDesign for what you knowDo not plan ahead! • No “what if…”• No big design up front• What most people find difficult about XP
A simple design…• Can easily be understood• Has higher quality, because it is stable• Is easier to change• Is faster to implement, has less errors
Uppsala university
2009-02-24 | #32@ UU/IT
What exit is the right one?
Uppsala university
2009-02-24 | #33@ UU/IT
FeedbackFrom system• Unit testing: test first, then code
From customer• Always present in room, takes part in acceptance
testsFrom team• Direct time estimates on new functionality
Uppsala university
2009-02-24 | #34@ UU/IT
User storiesSomething a userwants the system to do. Testable.
Uppsala university
2009-02-24 | #35@ UU/IT
User stories
Uppsala university
2009-02-24 | #36@ UU/IT
CourageNot to do more than requiredTo be able to re-factor code fast enoughTo review other’s code (and your own)Knowing when to throw away a bad solution
Issues• No place to hide!• This is quite a big problem
Uppsala university
2009-02-24 | #37@ UU/IT
RespectNot to break other’s codeAim for high qualityBe motivated and loyal
Uppsala university
2009-02-24 | #38@ UU/IT
What’s extreme?If tests are good, test all the time (start with Unit tests)If code review is good, always do reviews (pair programming)If iteration is good, deliver oftenSimplicity, do the simplest possible solutionUsers, have them in the same room
Uppsala university
2009-02-24 | #39@ UU/IT
XP’s 12 activitiesFine scale feedback• Pair programming• Planning Game (once per iteration, typically once a week)• Test driven development• Whole team (everyone needed is there)
Continuous process• Continuous Integration• Refactoring or Design Improvement• Small Releases (called “builds”, alpha)
Shared understanding• Coding Standards• Collective Code Ownership• Simple Design• System Metaphor
Programmer welfare• Sustainable pace
Uppsala university
2009-02-24 | #40@ UU/IT
Uppsala university
2009-02-24 | #41@ UU/IT
User stories
Uppsala university
2009-02-24 | #42@ UU/IT
Uppsala university
2009-02-24 | #43@ UU/IT
Is Agile user-centered?No:• Focus on code
No explicit way to handle usability• Involves users, maybe not the right ones, not in
the right environment• Hard for users to speak about their needs• Small increments – no overall view of the
situation and the interaction
Uppsala university
2009-02-24 | #44@ UU/IT
Is Agile user-centered?Yes:• User stories, by users• Direct communication• Simple representations • Iterations• Continuous testing and delivery• Change is welcome• About people, not processes
Uppsala university
2009-02-24 | #45@ UU/IT
ReadingAgile Modeling and eXtreme Programming• http://www.agilemodeling.com/essays/agileModelingXP.htm
Is Design Dead? Martin Fowler• http://martinfowler.com/articles/designDead.html
William Hudson: Adopting UCD within an agileprocess• http://www.syntagm.co.uk/design/articles/ucd-xp03.pdf
Larry Constantine: Process Agility and Software Usability• http://www.foruse.com/articles/agiledesign.pdf