Staff Scheduling

Schedule employees for shifts while respecting constraints like availability, skills, and workload limits.

Basic Example

Problem Description

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Schedule 4 nurses (Alice, Bob, Carol, Dave) for 3 shifts
(morning, afternoon, night) over 7 days.

Constraints:
- Each shift needs exactly 1 nurse
- No nurse works more than 5 shifts per week
- No nurse works two consecutive shifts
- Alice cannot work night shifts

What Savanty Does

1. Parses the problem to identify entities (nurses, shifts, days) and constraints
2. Generates an ASP program encoding the rules
3. Solves to find an assignment satisfying all constraints
4. Visualizes the schedule in a readable format

Sample Solution

Day	Morning	Afternoon	Night
Mon	Alice	Bob	Carol
Tue	Dave	Alice	Bob
Wed	Carol	Dave	Alice
...	...	...	...

Generated ASP Code

Prolog

% Entities
nurse(alice). nurse(bob). nurse(carol). nurse(dave).
shift(morning). shift(afternoon). shift(night).
day(1..7).

% Assignment rule: exactly 1 nurse per shift per day
1 { assign(N, D, S) : nurse(N) } 1 :- day(D), shift(S).

% Constraint: max 5 shifts per nurse
:- nurse(N), #count { D,S : assign(N, D, S) } > 5.

% Constraint: no consecutive shifts
consecutive(morning, afternoon).
consecutive(afternoon, night).
:- assign(N, D, S1), assign(N, D, S2), consecutive(S1, S2).

% Constraint: Alice no nights
:- assign(alice, D, night).

Advanced Example: Hospital Ward

Problem Description

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Schedule nurses for a hospital ward with the following requirements:

Staff:
- 6 nurses: Alice (senior), Bob (senior), Carol, Dave, Eve, Frank
- Senior nurses have 5+ years experience

Shifts:
- Day shift: 7am-3pm
- Evening shift: 3pm-11pm
- Night shift: 11pm-7am

Rules:
1. Each shift needs exactly 2 nurses
2. At least 1 senior nurse must be on each shift
3. No nurse works more than 40 hours per week (5 shifts)
4. Minimum 8 hours between shifts for each nurse
5. Carol and Dave prefer not to work together (soft constraint)
6. Weekend shifts (Sat/Sun) pay 1.5x - minimize weekend coverage cost

Schedule for 2 weeks (14 days).

Key Constraints Encoded

Hard Constraints:

• Shift coverage (exactly 2 nurses)
• Senior nurse requirement
• Maximum hours
• Rest period between shifts

Soft Constraints (Optimization):

• Minimize Carol-Dave pairings
• Minimize weekend costs

Sample Output

The solver finds a schedule that:

• Covers all shifts with 2 nurses each
• Ensures senior coverage on every shift
• Respects all rest and hour limits
• Minimizes the soft constraint violations

Variations

Part-Time Workers

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Workers:
- Full-time: Alice, Bob, Carol (max 40 hours/week)
- Part-time: Dave, Eve (max 20 hours/week)

Schedule all workers fairly while respecting their hour limits.

Skill-Based Scheduling

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Workers and skills:
- Alice: reception, billing
- Bob: reception, technical support
- Carol: billing, technical support

Shifts need:
- Morning: 1 reception, 1 technical support
- Afternoon: 1 billing, 1 reception
- Evening: 1 technical support

Assign workers to shifts matching required skills.

Rotating Schedules

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Create a 4-week rotating schedule where:
- Each nurse works the same pattern each week
- Pattern rotates through all shifts fairly
- No permanent night shift assignments

Tips

1. Define time periods clearly - "7 days" vs "Monday through Sunday"
2. Specify shift lengths if relevant for hour calculations
3. Distinguish hard vs soft constraints - must-have vs nice-to-have
4. Name your workers for clearer output