Practical guide
Focus at work: protect one useful hour
Workplace focus is easier when availability rules are visible and incoming requests have somewhere to wait.
The short answer
Reserve one hour, close chat and email, announce when you will return, and define which document, decision, or artifact must be different at the end.
Map every incoming channel
List chat, email, phone, colleagues, alerts, and browser tabs. Give each one a rule: silent, closed, or emergency-only. Without a rule, every notification becomes a fresh decision.
Group communication switches
A two-minute reply can make restarting expensive when it changes the problem in mind. Research on attention residue supports batching communication and closing the prior task with a short restart note.
A workable calendar block
Use ten minutes to prepare data, 50 to produce, and ten to walk and process urgent requests. Explicit borders survive a busy workplace better than a vague intention to have a focused morning.
Measure output instead of presence
Record the delivered artifact, attention switches, and remaining energy. If other people cause most interruptions, improve the availability signal. If you initiate them, move the distraction further away before the next block.
Research cited
These sources support only the specific mechanisms discussed above. Their methods, populations, and limits do not establish that one timer routine works for everyone.