# 104

Dear Rajko Ković, Miloš Milenković

I have read your paper

A two-step approach for selection of railway modernization projects based on Analytic Hierarchy Process

My comments

1- In page 2 you say “The solution to this problem requires aggregation of performances from different projects with multiple aspects, and with a mathematically sound approach – through the application of differing methods of different MCDM”

And how do you group and select the information involving different cases and different methods?

2- “no single method is ideal for application in portfolio management”,

And how do you demonstrate this assertion?

“Decision-making is a mental process based on tangible and non-material criteria”

I disagree with statement. Decision making is far from being a mental process.

Decision-making requires “wider and more complex understanding of the context, rather than any specific technique” (Vargas 2010).

Agreed

3- “The usage of AHP in PPM decision-making implies the identification of specific projects functionalities and presentation of collected results in a mathematicallyimpactful way, which connects the significance of a project and the strategic goals of an organization”.

Since when intuition and pair-wise comparison are mathematical?

4- “AHP is an organized structure of cross-analysis on hierarchical levels of strategic goals, criteria and alternatives, which are targeted by the decision-maker”

How can you perform cross analysis in a lineal, top to down hierarchy, and where all criteria must be independent?

5- ‘Resource management’ in AHP?

Strange, since the method ignore resources

6- “AHP and ANP use only quantifiable parameters, the number of criteria is usually limited to 10, and it’s not possible to compare more options”

You contradict yourself; first you say that AHP can handle complex problems, and now you say that it is limited to 10 criteria. Normally complex problems have many more tnar10 criteria and multiples interrelationships.

7- “AHP is a simple technique for project selection, which uses precise mathematical tools in a software application to support the validity of a decision and enable decision-makers to create a results simulation and justify their choice”

Your precise mathematical tools lare:

- Pair-wise comparison?

- Assigning importance of criteria by intuition?

- Assuming that the fundamental table is based on the Weber Fechter relationship between stimuli and results, and then equalling preferences to stimuli?

- Allowing a formula to correct the DM estimates?

- Assuming that what is in the mind of the DM applies to reality?

- Assuimin that trade-off is equivalent to weight?

- Using a hierarchy that does not allow transversal relationships?

- Assuming that criteria are independent?

- The only mathematical tool is using the Eigen Values, and it is also relative when the number of alternatives is > 3?

These are what you call ‘Precise mathematical tools”?

Could you please explain how the AHP software can support the validity of a decision, when this is taken at random?

I prefer not to comment on the balance of the paper

I hope my comments help

Nolberto Munier