Slashdot Mirror
In Search of the "Perfect" Pager Rotation?
jSpectre asks: "At my new job the Unix SA team has increased from 5 to 7. We're trying to work out a new, rotating on-call schedule and everyone has 'perfect' but conflicting ideas. Twelve weeks on and 6 off, 25 weeks on and 10 off. I thought someone out there must have come up with the perfect formula given N number of people you could rotate through the weekdays and weekend most efficiently. My google and web searches have come up with nothing. Does anyone know of a good formula/solution? The requirements are this, we have 7 people (but the forumla should ideally apply to N people) who should rotate through the weekdays (a 24 hour period) and the weekend (a 48 hour period). There is a desginated primary and a secondary person. They should be on for a few weeks and off entirely for a few. Sound like a good thesis/research problem for someone? By the way, Google comes up with a lot of people's schedules if you search for pager rotation. Tisk tisk."
This is a perpetual scrum in medical residency, too. We can't do back-to-back calls, which makes it harder than, "You cover this weekend."
0 - Get a big ass calendar with holidays and some pencils. Decide how many days/year each person will have to work. Break them down into 4 or so categories: weekday, friday, weekend, holiday are ours. Friday is annoying because you can't go out but not as bad as an 24h (weekend/holiday) day. If weekends are light, you could just have "weekday" and "friday + weekend" categories. Anyway, share around evenly.
1 - Holiday parity is a good place to start. Noone wants to get screwed both xmas and new year's. Ask for preferences and nail down someone for coverage for these and Labor day, the 4th, T-day, etc. They can trade later.
2 - Map out the conferences and people's known vacation blocks, anniversaries, exams, etc.
3 - Some people haven't adapted to a totally random fill pattern of coverage, so give people a choice of contiguous blocks/easy to remember patterns (M/W for the month of ___) or irregular blips.
4 - Schedule the parts where many are out of the office with whatever it takes. Subtract these and the holiday days from the totals each person has to work. Schedule the pattern-desiring people and people with evening classes/outside commitments/inability to show up if on a random schedule. Again revise the totals.
5 - Start marching through at the beginning, rotating through the N people available. Keep running track of the fridays/weekends, do a little stagger to keep the weekends from being the same person on the same day, and it will start filling out.
6 - Think outside of the month to fit those last days in. You don't have to fill months contiguously or in date order. If there is a new employee, it may be best to slack off a bit on them (no weekends) at first until they fill out their KB; this gives you some flex.
N - Nothing you can do will make the perfect schedule. You have to have one master list that is the last word, and on which everyone must record their trades. Leftover days are best distributed to the people who took the least holiday days or the dues-paying new hires.
N+1 - Write some open source software to do this. Acrimony might be less, and the legibility would be better for sure.