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The Doctor Rostering Problem - Asser Fahrenholz

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Chapter 3. <strong>The</strong> model and design 9<br />

⎧<br />

1 if on day i, doctor k has a shift<br />

⎪⎨<br />

j outside the house. It follows that<br />

bijk =<br />

the doctor is not available for the surrounding shifts<br />

⎪⎩ 0 otherwise<br />

⎧<br />

⎪⎨<br />

sij =<br />

⎪⎩<br />

⎧<br />

1 if on day i, doctor k has<br />

⎪⎨<br />

requested shift j off. <strong>The</strong> doctor is then<br />

cijk =<br />

available for the surrounding shifts<br />

⎪⎩ 0 otherwise<br />

l if on day i, shift j must be assigned 1+l<br />

doctors. This happens on noonshifts following weekends and<br />

holidays, and afternoonshifts preceding holidays<br />

0 otherwise<br />

<strong>The</strong> index j defines: 1: Night shift, 2: Noon shift, 3: Afternoon shift, 4: Evening shift.<br />

Furthermore, shift j is said to be an assignment shift (as) if it doesn’t lie on a holiday,<br />

nor a weekend and is not a night- nor evening shift.<br />

Let n be the number of days in the problem, and m be the number of doctors:<br />

i ={1, 2 . . . n}<br />

k ={1, 2 . . . m}<br />

In the following, I assume the schedule starts on a Monday, that the index of this day<br />

is 1 and that the schedule ends on a Sunday and the index of this day is n.<br />

I also define the sets of days:<br />

3.2 Hard constraints<br />

M : i%7 = 1 ∀i<br />

F : i%7 = 5 ∀i<br />

This section describes the constraints that must be satisfied for the solution to be feasible:

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