The XP Solution
After analyzing the mistakes the industry was making, we needed to come up with practical,
cost-effective
solutions. Clearly, Web development teams needed to adopt new development methodologies. These methodologies needed to stress customer involvement in the day-to-day decisions within the project, include incremental milestones of weeks rather than months, and allow for ongoing refinement of estimates based on actual progress. Project management would have to be redefined, not as software or advertising but as a new entity consisting of multidisciplined
teams
with close coupling to customer stakeholders.
We knew of XP in association with software development and wondered if it could solve the problems in Web development. Given the Web industry's essential differences from the software industry, could XP be as good a fit?
Web Development versus Software Development
XP methodology could
potentially
deal with a number of Web development problems. XP involves the customer, integrates teams, generates
maintainable
code, and, most important, divides the responsibility for project success between the developer and the customer and so creates an atmosphere of trust. But would XP map directly to the needs of Web projects? Extreme Programming was developed to resolve problems in software, not Web, development. There are a number of key differences between the two.
Teams
Web projects involve
multidisciplinary
teams made up of graphic designers, copywriters, Flash programmers, server-side programmers, interface programmers, testers, and project managers. Team
members
can't be isolated because decisions made by one affect the others, and the intersection and overlapping of skills make it
impossible
to set strict boundaries of responsibility. A series of questions and answers illustrates this:
Question:
Who is responsible for how the page displays?
Answer:
The designer and the interface programmer.
Question:
Who is responsible for how a function works between the server and the customer?
Answer:
The server-side programmer and the interface programmer.
Question:
How does the Flash element pull a weather forecast from a third-party application?
Answer:
Better ask the designer, the Flash developer, the interface programmer and the server-side programmer. Oh, and you'd better ask the customer about everything!
XP is very good at getting programmers to communicate among
themselves
and with customers. Web projects require a myriad of new disciplines. How does XP cope with this decision-making interconnectedness?
Support for Multiple
User
Environments
Most software projects create deliverables for one platform at a time. Different software versions are developed to handle different user environments. For example, the latest release of an application will have a version for Windows, a version for UNIX, and perhaps a version for Mac, depending on its audience. Unfortunately, in Web we don't have the luxury of separating out the product. There is only one version of the Web site, and it must be able to support multiple browsers on multiple operating systems
simultaneously
, running multiple screen
color
and resolution settings, not to mention modem speeds.
Worse
, not only do the system requirements vary depending on the Web site audience but they can change from the beginning of a project to the end.
How does Extreme Programming allow for the varied support needed in one product?
Testing
Web projects require unique testing practices to account for multiple customers, and they have an emphasis on how things look that is often unheard of in software projects. Testers have to be able to test interfaces in totally new ways. For example, page layout, design, screen colors, and screen resolution are all requirements that can be
tested
only by eye.
How does XP deal with the need for sense-based testing?
Rapid Deployment
Software developers have the luxury of large releases. The cost of a new version of the software forces the customer to plan releases
carefully
and to make them substantial revisions. Web projects can be deployed as often as the customer wants. Web XP projects need to harmonize continuous integration with new release practices.
How does XP accommodate the need for frequent deployment?
Customers
Software development needs a customer to set priorities, define the problem domain, and make key decisions, because it is the customer who understands the process that the software is trying to emulate. Web projects are
generally
the development of a corporate Web site or system and are often marketing vehicles new to the organization. Thus, it is hard to find an expert to
consult
. Web customers look to their developers for far more guidance than XP allows.
How can Extreme Programming help educate customers and increase customer satisfaction?
Quality
Many original Web sites were low-quality, brittle masses of code. Few Web developers used an object-oriented approach to development. Most used procedural languages, which made refactoring code or making changes to it much more difficult ”often sites were simply redeveloped each time enough changes were
requested
. Over time sites get worse, not better. New design patterns pioneered for software have to be created for Web sites.
How can XP help to improve quality?
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