Excel's Goal Seek and Solver are both "what-if" analysis tools, but they handle different levels of complexity. Here's a breakdown of how to use them:
Goal Seek :
- Purpose:
- Goal Seek is used to find the input value needed to achieve a desired output value in a single formula. It essentially works backward.
- It's ideal for situations where you have one variable to adjust to reach a specific result.
- How to Use:
- Set up your formula: Ensure you have a formula that calculates the output you want to change.
- Go to Goal Seek:
- Go to the "Data" tab.
- Click "What-If Analysis" and select "Goal Seek."
- Fill in the dialog box:
- Set cell: Enter the cell that contains the formula.
- To value: Enter the desired output value.
- By changing cell: Enter the cell that contains the input value you want to adjust.
- Click "OK": Excel will calculate the necessary input value.
- Example:
- If you have a formula that calculates profit based on the number of units sold, you can use Goal Seek to find out how many units you need to sell to reach a specific profit target.
Solver :
- Purpose :
- Solver is a more advanced tool that can handle complex optimization problems with multiple variables and constraints.
- It's used to find the optimal solution (maximum, minimum, or specific value) for a target cell by adjusting multiple changing cells, subject to constraints.
- How to Use :
- Enable Solver:
- Go to "File" > "Options" > "Add-Ins."
- In the "Manage" box, select "Excel Add-ins" and click "Go."
- Check the "Solver Add-in" box and click "OK."
- Set up your model: Create a worksheet with your formulas, changing cells, and constraints.
- Go to Solver:
- Go to the "Data" tab.
- Click "Solver."
- Fill in the Solver Parameters dialog box:
- Set Objective: Enter the cell that contains the formula you want to optimize.
- To: Select "Max," "Min," or "Value of" (and enter the desired value).
- By Changing Variable Cells: Enter the cells that you want Solver to adjust.
- Subject to the Constraints: Click "Add" to enter your constraints.
- Select a Solving Method: Choose a solving method (e.g., Simplex LP, GRG Nonlinear, Evolutionary).
- Click "Solve": Solver will calculate the optimal solution.
- Example :
- You can use Solver to determine the optimal production levels for multiple products, subject to constraints such as resource availability and demand.
Key Differences :
- Complexity: Goal Seek handles single-variable problems, while Solver handles multi-variable optimization problems.
- Constraints: Solver allows you to define constraints, while Goal Seek does not.
- Optimization: Solver can find optimal solutions (maximum or minimum), while Goal Seek only finds a specific target value.
