• HEAD TO HEAD
AGILE VS. WATERFALL The rivalry between Agile and waterfall processes relates to the scale and scope of a project. Agile’s advocates point to its iterative process that delivers frequent milestones and the ability to change directions according to external factors. But by formulating scope at the outset, waterfall’s sequential process may improve governance, especially highly regulated infrastructure projects. Both methods have challenges. Which is best? We ask two experts.
INTERVIEWS ADELINE TEOH
PROCESS COACH, FACILITATOR & CONSULTANT AT PROCESS PEOPLE
NATIONAL MANAGER FOR PROJECT CONTROLS & RISK AT AQUENTA CONSULTING
• Agile is… A set of guiding principles for building software or ‘iterative development’ such as Scrum, Kanban and XP. They have rules, while Agile-proper has 12 principles. For software projects Agile is best for early and frequent delivery while adapting to customer requests. • Only Agile would do for… An application development project I once worked on. Neither the developers nor the business understood the potential of the app or its use for a particular customer. Two-week iterations enabled experimentation. Developers answered business needs, got feedback, agreed changes and iterated without wasting time on an unsuitable product. The business could not communicate exact requirements and sign off on a scope document at the start. Even when we meet exact customer requests, such as in waterfall projects, often the customer feels dissatisfied. • However… I’ve steered clients away from, or postponed, Agile development. Lack of knowledge, experience and support may lead to misunderstandings of the intention of Agile. Where there is a cross-functional, self-organising team, Agile has significant benefits. • Agile is best… For projects that will change scope.
Cost-effective, early delivery of value to the business comes through regular iterations, involving the customer in the project and reacting rapidly to change. Agile prioritises customer satisfaction, creating a product that reflects what they need at the time of delivery and not what they asked for at the start.
• WHICH IS BEST FOR YOUR PROJECT? 28 AIPM.COM.AU
• Waterfall is… A sequential delivery process where progress flows downwards, like a waterfall, through feasibility, conception, initiation, design, construction, commissioning and maintenance. Originating in the manufacturing and construction industries, waterfall models structured physical environments in which changes are minimised. • Only waterfall would do for… Logic-driven projects including construction, manufacturing, vendor software installation and public works utilities. The scope is set upfront through requirements with cost, schedule and performance as variables. Time spent at the start to define scope with documentation mitigates delays, overruns, claims and disputes. It identifies risks and uncertainties and provides clear allocation between stakeholders. • However… It is not ideal for projects that will evolve, that have changing client requirements or an undefined endpoint. For example, the client can choose to accept a less-than-complete outcome if enough of the requirements were met. If the cost, schedule and performance are set with the scope as the variable, other approaches than might be more suitable. • Waterfall is best… For delivery of complex projects. It identifies and manages risks and uncertainties and brings the highest probability of success. The client’s goal should dictate which approach is used and this relies on their culture and how they define success. Waterfall works best for the needs and capabilities of most clients, particularly those who identify requirements at the start.
Tell us your experience with Agile and waterfall. When would you choose to use one approach over the other, and can the two processes work together? Search for the AIPM LinkedIn group at www.linkedin.com/grp/.
Project Manager June 2014