[nzjames]

My issue with GTD and trying to use a todo system is there seems to be an assumption that you are able to quantify the time/effort to do each of your daily tasks.

Developing software and solving problems all day I can't often gauge by looking at a list how long different tasks are going to take or how much they'll make my head hurt.

I can do the straight forward things quickly, I try to stay on top of things I need to do but have been putting off. But I always seem to get stuck and fill up todo lists with thing's I've go no idea how to get off the lists and I don't believe it is as simple as breaking them up into actions.

I don't need a method for managing tasks, I need something to structure and support arbitrary problem solving.

[jorleif]

Exactly, there would need to be something like GTD for problem-solving. E.g. similar to the two-minute rule, one would have something like the two hour rule: "If you can't solve the core problem in two hours, ask someone for help".