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OPA Solver: A Solver for Multiple-Attribute Decision-Making Problems

Mahmoudi, Amin

OPA Solver Version 1.00 (Excel-Based):

The Ordinal Priority Approach (OPA) is a new development in multiple-attribute decision-making context. The OPA can calculate the weights and the ranks of the experts, alternatives, and attributes simultaneously using simple steps. It supports group decision-making without using averaging methods. This software can help you to solve multiple-attribute decision-making problems using the OPA after a few clicks.

OPA Solver Version 1.2 (Web-Based): Web-based solver can be found at OPA Solver 1.2

Before using the OPA Solver v1.00, you should check the following requirements on your system: 1- Please enable "Trust Access" in the Excel software using the following address: Windows: 1. Click the "File" tab. 2. Click on "Options". 3. Click "Trust Center", and then click "Trust Center Settings". 4. "Macro settings" 5. Select the "Trust access to the VBA project object model" check box, and then click OK. Mac: 1. Click the "Excel" tab 2. Click on "Preferences" 3. Click on "Security" 4. Select the "Trust access to the VBA project object model" check box. 2- Please install the "Solver" on your Excel. You can install the Solver with clicking on "Install Solver" in this software. It should be noted that "Trust Access" should be activated before installing "Solver". Note1: This file cannot solve large-scale problems due to Excel limitations on the number of constraints. Also, Tie ranks for the alternatives cannot be entered but Tie ranks for criteria and experts are allowed. If you face any problem regarding the above requirements, please contact with Note 2: Before using the OPA Solve sheet, please see the examples 1 to 3 carefully. Example 1 is single decision-making. Example 2 is group decision-making with incomplete data and Tie ranks in criteria. Example 3 is calculating the weight of criteria only. After that, please go to "OPA Solver v1.00" sheet and solve your problem. Note 3: The Model and Equations of the OPA for using in academic papers are provided in this software. Please visit for new updates and studying learning materials.
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  • Ataei, Y., Mahmoudi, A., Feylizadeh, M. R., & Li, D. F. (2020). Ordinal Priority Approach (OPA) in Multiple Attribute Decision-Making. Applied Soft Computing, 86, 105893.

  • Mahmoudi, A., Deng, X., Javed, S. A., & Zhang. (2021). Sustainable Supplier Selection in Megaprojects: Grey Ordinal Priority Approach, Business Strategy and the Environment, 30 (1), 318-339.

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