Knowledge work sometimes gets this mystical quality about it. Sure, knowledge workers don’t produce widgets, they produce information or something.
But there are skills and lessons to be learned from the world of manual labor and industrial production. A carpenter at a job site is working on one thing at a time. This cabinet has to get built and installed. Then, I can move on to framing that doorway and putting up drywall. And after those are both done, I’ll take lunch. No bouncing between jobsites (aka projects). Even though there are multiple tasks to get done, they all fit under the single umbrella of the current location.
Knowledge workers can simulate job sites. By restricting the tasks you can work on to only those related to a specific project, you can avoid getting pulled in a million different directions with open loops, new emails, and other “offsite issues.” Those things can get taken care of the next time you visit the relevant job site. Until then, you have a job site to attend to and give your full attention.