Software Engineering: Agile Methods (Just the Quotes)

"Agile development methodologies promise higher customer satisfaction, lower defect rates, faster development times and a solution to rapidly changing requirements. Plan-driven approaches promise predictability, stability, and high assurance. However, both approaches have shortcomings that, if left unaddressed, can lead to project failure. The challenge is to balance the two approaches to take advantage of their strengths and compensate for their weaknesses." (Barry Boehm & Richard Turner, "Observations on balancing discipline and agility", Agile Development Conference, 2003)

"It is a myth that we can get systems 'right the first time'. Instead, we should implement only today’s stories, then refactor and expand the system to implement new stories tomorrow. This is the essence of iterative and incremental agility. Test-driven development, refactoring, and the clean code they produce make this work at the code level." (Robert C Martin, "Clean Code: A Handbook of Agile Software Craftsmanship", 2008)

"Agile approaches to software development consider design and implementation to be the central activities in the software process. They incorporate other activities, such as requirements elicitation and testing, into design and implementation. By contrast, a plan-driven approach to software engineering identifies separate stages in the software process with outputs associated with each stage." (Ian Sommerville, "Software Engineering" 9th Ed., 2011)

"Agile methods universally rely on an incremental approach to software specification, development, and delivery. They are best suited to application development where the system requirements usually change rapidly during the development process. They are intended to deliver working software quickly to customers, who can then propose new and changed requirements to be included in later iterations of the system. They aim to cut down on process bureaucracy by avoiding work that has dubious long-term value and eliminating documentation that will probably never be used." (Ian Sommerville, "Software Engineering" 9th Ed., 2011)

"Agile development methods require a disciplined approach to ensure that customer feedback, continuous testing, and iterative development actually lead to frequent deliveries of working, valuable software." (Michael Hüttermann et al, "DevOps for Developers", 2013)

"The advantages of Agile processes, including Scrum and Kanban (a method for delivering software with an emphasis on just-in-time delivery), are often nullified because of the obstacles to collaboration, processes, and tools that are built up in front of operations." (Michael Hüttermann et al, "DevOps for Developers", 2013)

"Many problems stem from a premature attempt at scaling Agile within the organization. The nature of the transformation is such that it is unrealistic to plan upfront for an 18-month organization-wide change program to go from status quo to continuous delivery. People try nevertheless, and when the outcomes don’t materialize, they say Agile doesn’t work." (Sriram Narayan, "Agile IT Organization Design: For Digital Transformation and Continuous Delivery", 2015)

"This is what the Agile Manifesto means when it says responding to change over following a plan. To maximize adaptability, it is essential to have good, fast feedback loops. This is why there is so much emphasis on iterative development." (Sriram Narayan, "Agile IT Organization Design: For Digital Transformation and Continuous Delivery", 2015)

"Heart of Agile is a meme. Heart of Agile is four words stripped down to nothing. It contains only four words – collaborate, deliver, reflect, improve." (Alistair Cockburn, [interview] 2017)