I was working on a few projects where SCRUM was used. All those projects - with only one exception - were screwed. On one project Daily Standups were always more than an hour (of the most valuable and most productive morning time) where we/they would talk mostly about topics I wasn't involved in. Reviews were 3 to 5 hours every second week... On another project estimates were in "story points" and projects manager had to "recalculate" them into man-days in order to be able to communicate with customers... And so on... Not a help for developers and for customers either... But on my current project - it is working! It is lightweight (most standups are finished in 5 minutes, Sprint Reviews are mostly finished in 30 to 75 minutes every third week), Sprint Plannings are short because we have regular Groomings (twice a week). Sprint Retro is also short (30 minutes). Groomings may be time consuming, but they are needed in order to understand what needs to be done in details. We estimate in man-days and break all tasks larger than 8 or 12 man-days into smaller one. Everybody must be able to pickup any task. If one finished his work, he must take the task with highest priority from the list (for current sprint). Sprints are 3 weeks long. I have to say this is the first time it is working for me as a developer. And business ("non-technical") people are satisfied, because they have much more insight into development and understand better how everything works. All new wishes and requests flow into Backlog and are prioritized and then groomed and estimated. So we spend in average weekly 30 minutes for ALL standups and 3 hours for grooming (which is actually part of planning). It is VERY lightweight and I like it the first time in my life. We are doing it in this way for 2 years now and nobody has any plans to change it.