The Improving Projects blog from Huge IO (UK & Ireland) is primarily about products, organisations and projects... and how to improve them. As well as musings on agile processes, software engineering in general, and methods like Kanban and Scrum, there's advice here too for users of process planning, execution and improvement tools - and the metrics they can provide. https://uk.huge.io
Is it possible to implement an agile project without overhauling your requirements process? I think not. The key economic benefits flow from agile methods ability to reduce "work in progress" compared to traditional methods [Anderson]. This means specifiers must take a much lighter approach to distant requirements and have much greater involvement, for example as "on-site customers" or product owners, in requirements currently being implemented.