CSC/ECE 517 Fall 2007/wiki3 10 tm

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The Agile debate. Perhaps the most prominent controversy in o-o design today is whether it is possible to do a robust design with as little advance planning as agile methodologies recommend. Research this issue, on the Web and in the ACM DL, and report (fairly) on the major arguments of both sides, and on the evidence for both positions.

What is 'Agile Methodology'?

Agile Methodology was introduced as an iterative approach for developing software as a counter to waterfall approach. Where the five main phases of waterfall (requirement, design, coding, integration, testing) are practiced through every iteration. Moreover, it suggested several practices to enhance the software developments, see next figure from [http://txpug.editme.com/files/Lec2004Jul26/rupvagile.1.ppt "Finding Agility -�A comparison of RUP and Agile"], *.PPT .


Many Agile methodologies were introduced in the last decade (XP, Scrum, DSDM, FDD, Adaptive, Crystal). It would be difficult to introduce every aspect of these methodologies in this wiki. That is why, This wiki will concentrate in the most popular agile methodology, XP (eXtreme Programming).

Comparison Basis for Robust Design

A comparison between Agile methodologies and Waterfall methodology is found to be a little out of scope, as the advantages of iterative methodologies already recognized. That is why the current wiki will concentrate to compare with other iterative methods, such as RUP (Rational Unified Process). RUP share many of Agile's practices. Other practices can be immigrated from XP to RUP, or vise versa. Other features will still be unique to XP or in RUP. Next figure outline these practices, from [http://txpug.editme.com/files/Lec2004Jul26/rupvagile.1.ppt "Finding Agility -�A comparison of RUP and Agile"], *.PPT .


In the current wiki we will try to test the Agile Manifesto and its related practices relative to design quality. These found to be the comprehensive basis for comparison as it provide the basis Agile methodologies trying to establish over other methods.

Individuals and Interactions Over processes and tools

Agile methodologies clearly state their believe that people is the main driver to project sucess, rather than the process and the tool. Agile Methodologies encourage individuals and their interaction through several practices and principles;

  • Motivated individuals and Self organized team: Planning Game, Collective ownership.
  • Face to Face Communnication: Pair programming, Open space, On-site customer, Planning game.
  • Sustainable Base.

Critique

  • Requires too much cultural change to adopt.<ref name= "ExtremeProgrammingRefactored" >Extreme Programming Refactored</ref>
  • Go against "Human Psychology": many human factor might limit or currupt the process, such as: People prefer to follow a process, No milestones, People self-interest, mini-dictatorships, Knowledge Monopolies, Resource management vanish, customer dissatisfaction.<ref name= "KevinBlog2007" >Kevin Brady Blog"</ref>
  • The cost efficiency of pair programming is questionable.<ref name="mcbreen"></ref>
  • No Documentaion is acquired, just keep it minimal! <ref name= "ExtremeProgrammingRefactored" >Extreme Programming Refactored</ref>



Working software Over comprehensive documentation

Agile Methodologies shows strong customer orientation by providing incremental delivery of working software. This will decrease also the confusing if integration happen once and become easier to zoom in the bug(s). Agile methodologies support this concept by small releases and continuous integration.

Critique

  • Deliver to whom: In many times the customer(s) is not interested enough to use incomplete software.
  • 2-8 weeks releases is too short to accomodate.
  • Only works with senior-level developers, you need to gather requirements, test, code, refactor the code, integrate, release and PLAN.Developer need to do all this without stopping to design nor to give a deep thought about it.
  • Oral communication does not provide presistance and available source.
  • It is very difficult to keep the code, metaphors and user stories very clear to compensate the lack of necessary documentation!

Customer collaboration Over contract negotiation

While Agile methodology keep a broad meaning of the customer, which can be a member of the team, another part of the company or a contract customer. It still aquire his/her existance with the team. Which create a strong communication between the cusomter and company.

Critique

  • Can lead to more difficult contractual negotiations
  • This might make the customer controlling the process, or not realizing what his buissness really need.
  • Place large responsibilty in the customer, and no responsibility in the developer to learn more by himself about the bussiness.


Responding to change Over following a plan

Agile Methodologies incorporate the uncertainity exisiting in the project by creating an agile process that doesn't place planning further than exsitng iteration. This will reduce the cost of planning, and re-planning again. This principle is supported by many practices as incremental planning, refactoring and delaying decisions.

Critique

  • Incorporates insufficient software design.


Agile Methodologies' Real Manifesto

XP/Agile's practices are introduced to achieve certain values (Communication, Feedback, Courage, Simplicity, Respect). It is true that these practices will help to provide the best environment for these values to grow. Nevertheless, many of these practices acquire the existence of these values in the project, the company, the management, the individuals, and moreover the customer. Certain enough these values represent moral and professional values that should exist in every social and individual system. Nevertheless, we recognize their variation in every system. Moreover, many of these values might be out of the control as simplicity of the project or the courage of the customer. The author think that is why Agile approach will give even a better results in different area such as R&D or education, see links.

The question will be "Which should exist first the values -the egg- or the Agile methodology -the chicken-."

Conclusion

Agile methodologies provided a framework for software development. These methodologies not mint to be for every project, company and/or person. To gain the promised savings in the documentation, architecture and process, you need more than Agile practices; You will need Communication, Feedback, Simplicity, Courage, Respect existing in your company, project, individuals and in the customer. If you can't achieve these conditions, then you will need to be assisted with more documentations, design and process. Still Agile methodology will provide you with a lot of useful tools, you can pick and match what is suitable for your company, project, customer and personality.

External Links by Side

Arguments *Against* XP

Arguments *Support* XP

Success Stories

External Links by Field

Programming

Education

Project Management

R&D

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