In this blog post, Jim Bird discusses the issues of estimating in software development. He starts by reminding some of the modern lean concepts that condemn estimation. For him, this is applied mainly in context where delivering is more important than predictability.
Thus estimating can maybe be ignored in small teams and certain contexts like maintenance. Jim Bird affirms however that dropping estimation will not “work for large projects and programs with lots of inter-dependencies and interfaces, where a lot of people need to know when certain things will be ready. It doesn’t work for large teams where people don’t know the system, the platform, the domain or each other well enough to make good quick decisions. And it’s not good enough when something absolutely must be done by a drop dead date – hard industry deadlines and compliance mandates.” His conclusion is that you could sometimes get along without estimating, but you shouldn’t bet on it.