Agile development

The audience at the Effective IT Summit 2005 responded enthusiastically when asked by Fred Tingey, head of IT at financial services giant BNP Paribas: "How many of you develop your software using the ‘waterfall method'?" Tingey then surprised them: "All of you who are doing projects this way are doing it wrong."



Technology visionaries have long heralded web services as a revolutionary way of revitalising the enterprise – one of those much lauded ‘paradigm shifts’.

In 2004, car rental company Avis tested that claim with a vast project to replace its 30-year old rental system. Avis’ core IT system Wizard was created in 1973. Over the years, it had grown increasingly complex as thousands of new Avis offices were added and the requirement grew for the processing of ever-more fine-grained detail. Eventually, the business demand for timely, accurate information became too great for the system to handle.

According to David Harris, CIO for the Avis Futures project and now COO of OffTwo, the company formed by the management team behind the project, Avis realised it needed to replace Wizard’s proprietary interfaces with industry standard technologies. The rental company needed to be able to integrate systems – both internally and with partners – better.

The duplication of effort which had resulted from expansion – for example there were three different booking engines worldwide – needed to be eradicated. Many business agreements in different languages were hard-coded in the system, making changes to it complex.

Harris quickly realised that web services – using XML standards to build a service-oriented architecture – offered the best solution. SOA’s incremental nature means it can be enhanced as and when the business case dictates. “With SOA the ROI comes over a series of projects, building up over time,” says Harris. “However that can make it difficult to sell to a business wanting immediate return. It is still difficult for the business and technical side of an organisation to talk in the same language. While you might hear great concepts, delivery is still the key.”

SOA enabled Harris’s team to have more services supported by different access points, such as mobile phones and PDAs, which increased its speed of service. In his words, it “put the business back in the hands of the business people.”

Employees could check cars in and out using handheld devices and customers could locate their rental car on their mobile. New applications, like customer preferences, were incorporated. The project was delivered six months early and 30% below the original estimate.  


The waterfall method helps software developers break down projects into a hierarchy of stages, activities and tasks, which can then be represented in a so-called waterfall diagram.

The weakness of this approach is that it is a staid, ungainly approach to development, where problems only come to light when it is too late, says Tingey. "Individual parts of a system may work but it is virtually certain that when you put them all together the system will not." Even if it does work, the system created may no longer meet the end user's needs because its rigidity will prevent feedback being fed back in.

His arguments are supported by research firm The Standish Group, which noted that only a third of IT projects in 2003 were successful and the majority delivered half of the initially required functionality.

Instead, software development should rely on agile methods, says Tingey, focusing on iterative development that is constantly aligned to business requirements. This approach helps reduce risk and shorten development times.

BNP Paribas used this so-called ‘agile development' method to get one of it failing IT projects back on track. Eight developers had started a six-month project to create a workflow system for credit requests and limits. However six, including the leader, left within three months of each other.

The project was completed just a month behind schedule, principally because new developers started immediately with testable working software rather than half-finished components. "Everything that works was developed iteratively," says Tingey.

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Ben Rossi

Ben was Vitesse Media's editorial director, leading content creation and editorial strategy across all Vitesse products, including its market-leading B2B and consumer magazines, websites, research and...

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