What an interesting challenge you bring here. Thanks for it. Make sure you are comparing alternatives with a consistent criterion.
Indeed, dealing with uncertainty, incomplete information or unmatchable criteria between alternatives are common challenges in multi-criteria decision making (MCDC). Usually, when some criteria values are unknown you can (A) Use a standardization (set a default value for uncertain value). or (B) Apply fuzzy/intuitionistic or neutrosophic logic operators *1.
Now, from what I heard, you have a set of different alternatives that have attributes that do not match with each other. M1 alternative does not have one of the attributes.
However, the way you approach the fix depends on your decision goal. For instance, if your goal is to select the most optimal material, you might find relevant if some material has or not has hardness property. Apart from representing hardness with a range of integers or float numbers you can set a numeric boolean number: 1 for yes, 0 for no. Or a fuzzy number. (A scale from 0 and 1 for example).
Make sure you understand how the ELECTRE method works. *2-3
Try using a boolean or fuzzy operator for those null values and let me know if you have consistent results.
You may want to consider TOPSIS algorithm as well. *4-5
I hope it helps!
REFERENCES:
- 1 Mardani, A., Nilashi, M., Zavadskas, E. K., Awang, S. R., Zare, H., & Jamal, N. M. (2018). Decision-Making Methods Based on Fuzzy Aggregation Operators: Three Decades Review from 1986 to 2017. International Journal of Information Technology & Decision Making, 17(02), 391–466. doi:10.1142/s021962201830001x
- 1 Pramanik, S., Biswas, P., & Giri, B. C. (2015). Hybrid vector similarity measures and their applications to multi-attribute decision making under neutrosophic environment. Neural Computing and Applications, 28(5), 1163 doi:10.1007/s00521-015-2125-3
- 2 Roy, Bernard (1968). "Classement et choix en présence de points de vue multiples (la méthode ELECTRE)". La Revue d'Informatique et de Recherche Opérationelle (RIRO) (8): 57–75.
- 3 Electre method for Multiple Criteria Decision Making. Retrieved from https://www.youtube.com/watch?v=wOwP-EFlcVU
- 4 Hwang, C.L.; Yoon, K. (1981). Multiple Attribute Decision Making: Methods and Applications. New York: Springer-Verlag
- 5 Hwang, C.L.; Lai, Y.J.; Liu, T.Y. (1993). "A new approach for multiple objective decision making". Computers and Operational Research. 20: 889–899