How to handle emerging sub tasks and dismissed tasks-in-progress

Question

When working on a (programming) task, often I discover that the goal I set cannot be achieved the way I thought: either (1) it must be split up, or (2) abandoned altogether. In the Pomodoro book, this is called a qualitative estimation error.

1. Splitting might be necessary when I overlooked some sub task, thinking it could be done within this task, but it is so large that it should be a task by itself.

2. Abandoning happens for example when I wanted to use design pattern X, but when coding it, it appears to me that design pattern Y is a much better match. The task 'implement design pattern X' is then no longer useful.

How do I handle this kind of estimation errors task wise?

I'm using a hybrid of Personal Kanban and Pomodoro, but the problem applies to both.

1. Should I consider the sub task separate from the main task for estimates? If I do, the estimate for the main task will go down, which seems counter intuitive to me. Also, do I keep the main task in my "Doing" column on the Kanban board?

2. Should I just replace the task with the new task? If I do, do I count the time spent towards the new task? Where do I leave the old task on the Kanban board? It's not done, but it never will be.

Answer 1

In either case you should not reset the timing of your Pomodoro.

In the case of Split Up, let the task be in your Doing List.

In the case of Discarding the Task - do the obvious, substitute the task of "Design X" to "Design Y".

One very important point here is "Do not think much", just go for it.