As an entrepreneur, I'm always looking for ways to use my time more efficiently. Several years ago I took a time management course while working on my dissertation in which the primary message was to set a hard stop time every day. This counter intuitive approach was based on the notion that if one knows they have to stop at a particular time, they will work more efficiently up until that time. Most people focus on the start time (I'll start hitting it hard at 8 AM on the dot!) but without a stop time they drag on through the day and into the night; they might end up sitting at their desk for more hours than the guy who stopped at 6 PM but they don't necessarily get as much done.
As a technologist, I find that often I have to apply the set stop time approach on a per project basis before outsourcing a given job. Just this past weekend I was stuck on a problem with a software package my company recently acquired. I was tempted to keep tinkering with the package but after about 8 hours I sought help from a news group and learned that the software package has a poorly documented bug for which a patch existed. I wish I had applied the set stop time approach on this project; e.g., I'll work on this package for X hours after which I'll seek help from a consultant (hopefully X would have been a lot less than 8 hours).
I'm wondering if other entrepreneurs agree with this approach or does it only apply to dissertation disserters. How has this or a similar approach been manifest in your work?