Excel Solver for Optimization
Solver finds optimal solutions for complex problems with multiple variables and constraints. It's perfect for resource allocation, scheduling, budgeting, and linear programming.
Enabling Solver
1. File → Options → Add-ins
2. Manage: Excel Add-ins → Go
3. Check "Solver Add-in" → OK
4. Now available: Data tab → Analyze group → Solver
Example 1: Production Optimization
Problem: Maximize profit with limited resources
Setup:
Product A: $40 profit, 2 hours labor, 3 units material
Product B: $30 profit, 1 hour labor, 2 units material
Constraints:
- Maximum 100 hours labor available
- Maximum 120 units material available
Cells:
B1: Units of A (to optimize)
B2: Units of B (to optimize)
B3: =40*B1 + 30*B2 // Total profit (objective)
B4: =2*B1 + 1*B2 // Labor used
B5: =3*B1 + 2*B2 // Material used
Solver Settings:
Objective: B3 (maximize)
By changing: B1:B2
Constraints:
- B4 <= 100 (labor limit)
- B5 <= 120 (material limit)
- B1 >= 0, B2 >= 0 (can't produce negative units)
Result: Optimal production mix for maximum profit
Example 2: Budget Allocation
Problem: Allocate $10,000 marketing budget across channels
Channels: Social Media, Email, PPC, Content
Each has different cost per lead and conversion rates
Objective: Maximize total conversions
Constraint: Total spend <= $10,000
Each channel minimum $500, maximum $4,000
Solver finds optimal allocation across all channels
Example 3: Staff Scheduling
Problem: Minimum staff to meet hourly demand
Requirements:
Mon-Fri 9am-5pm: 10 employees needed
Weekends: 5 employees needed
Employees work 5 consecutive days
Objective: Minimize total employees
Constraints: Meet minimum requirements each day
Solver determines optimal hiring schedule
Setting Up Solver
1. Define Objective Cell
What to optimize (maximize, minimize, or target value)
Example: Maximize profit, minimize cost
2. Variable Cells
Cells Solver can change to reach objective
Example: Production quantities, budget allocations
3. Constraints
Limitations and requirements
Examples:
- Budget <= $10,000
- Inventory >= 100
- Labor hours <= 40
- Variables must be integers
- Variables >= 0 (non-negative)
Solver Parameters
Solving Method:
- Simplex LP: Linear problems (best for most cases)
- GRG Nonlinear: Smooth nonlinear problems
- Evolutionary: Complex, discontinuous problems
Options:
- Max Time: How long to search for solution
- Iterations: Maximum calculation iterations
- Precision: How close to target
- Integer Constraints: Force whole numbers
Common Use Cases
Portfolio Optimization
Maximize returns while:
- Meeting risk tolerance
- Diversification requirements
- Minimum/maximum position sizes
Transportation Problem
Minimize shipping costs from:
- Multiple warehouses
- To multiple destinations
- With capacity constraints
Product Mix
Maximize profit given:
- Limited raw materials
- Production capacity
- Minimum order quantities
- Storage limitations
Solver vs Goal Seek
| Goal Seek | Solver |
|---|---|
| Changes 1 variable | Changes multiple variables |
| No constraints | Handles many constraints |
| Reaches specific value | Maximizes/minimizes |
| Simple problems | Complex optimization |
Tips for Success
- Start with reasonable initial values
- Add constraints one at a time and test
- Use Simplex LP for linear problems (fastest)
- Make integer constraints only when necessary
- Save your model to rerun with different parameters
Pro Tip: Solver can save multiple scenarios. After finding a solution, use Scenario Manager to save it, then run Solver again with different constraints to compare options.
← Back to Excel Tips