Dear Mr. Rukhshanda Rehman , Muhammad Sagheer Aslam , Elzbieta Jasinska, Muhammad Faisal Javed and Miroslava Gono

I read your paper

“Guidelines for the Technical Sustainability Evaluation of the Urban Drinking Water Systems Based on Analytic Hierarchy Process”

These are my comments

1- You say “integration of technical, environmental, social, economic, and institutional elements of sustainability is defying and perplexing in terms of its application and evaluation”

Obviously, the paper addresses the subject in the right way, since all these aspects participate in the evaluation.

2- You say “This led to the development of a hierarchy from criteria to factors and from factors to sub factors, making a case for the utilization of an analytic hierarchy process (AHP) for multicriteria analysis (MCA)”.

Well, if you say that integration is necessary, as it is, then you can’t use AHP for evaluation, but perhaps ANP or any other MCDM method, because AHP works with independent criteria (Explicitly uttered by Saaty).

3- Your title announces sustainable evaluation, which means integration, but it does not imply independent evaluation of each criterion and then, adding up results, or, mathematically, (A U B U C) (union), (assuming three criteria or areas), but the consideration of all criteria at the same time, or(A∩B∩C) (intersection). It can be seen using the Venn diagrams defining sustainability and considering three areas (Economics, Social and Environment). Sustainability is expressed by the area that depicts the intersection of the three areas, not by the sum of them.

4- When you state “Urban water management is still a complicated and dispersed field that relies on conventional, technical, and linear management”, it is, in my opinion, incorrect, because this is not precisely a linear management, but a network management.

5- Table 1 is excellent, since depicts that criteria must be selected by stakeholders and not by the DM

6- In Table 2 you compute the weights from subfactors pertaining to criteria ‘Design’ and ‘O&M’.

In reality, some of these factors interact, for instance, design depends on construction quality and vice versa, as well with water quality. As an example, drinking water treatments steps are, coagulation, flocculation, sedimentation, filtration and disinfection, and this is related with quality of water. You will get better quality of water using ultrafiltration and including certain chemicals, or reverse osmosis, therefore, quality depends on the prior treatment. Therefore, they can’t be just added as you do.

There could also be that treatment is related to the water source. In many places, underground water has natural contaminants, generally minerals and including arsenic. Obviously, the treatment is different from other sources, as large rivers.

7- One distinctive feature of your paper is that it rightly considers what stakeholders mean and which are they. This is normally not seen in other papers, although its importance is capital.

8- You use the pair-wise comparison procedure between two criteria or two factors. If you compare for instance, criterion C1 = Water treatment and criterion C20 = Social issues, you can use two experts, each one very knowledgeable in water treatment and in social issues respectively, but both ignorant on the other expert activity. Now, how do both experts can reach an agreement regarding which criterion is more important than the other, if each expert knows nothing about the other?

That is, the engineer may be very eager to support the use of say reverse osmosis, and the social worker also very eager in supporting an affordable price for the consumer, considering that reverse osmosis is expensive. How can they reach and agreement, let alone to put a value to that preference? And also, there could be a doctor whose opinion is that the amount of a contaminant is of no concern.

9- When you take into account all of these facts, what is the importance if there is or not consistency?

I hope that these comments may help.

Regards

Nolberto Munier