W4_BUD_Multiattributes Decision Making (Compensatory Models)

1.    Problem Definition

This blog posting discusses a W3 blog post’s case study with a different approach. In W3 blog posting, the analysis performed using the Non Compensatory Model, whereas in this W4 blog will be analyzed using Compensatory Models.

Waste water collection pond in our plant has been operating for more than five years and this year is scheduled for cleaning. Prediction of the amount of sludge that will be generated as much as 1000 m3. Because the sludge is hazardous waste, there will be additional cost for sludge disposal. I was assigned to select the optimum cleaning and sludge processing method in terms of cost, time, safety and environmental impact.

2.    Feasible Alternatives

There are three alternatives for cleaning and sludge processing method, as follow:

1. Sludge is direct transferred to container.

2. Sludge is processed using Decanter Centrifuge to reduce the volume before transferred to container.

3. Sludge is processed using Geotube to reduce the volume before transferred to container.

 

3.    Develop the Outcomes for each Alternative

Table below shows the detail outcomes for each alternative:

 

 

4.    Acceptable Criteria

Based on the Ordinal Ranking (ref. W3 blog post) then determined weighting for each of the following attributes:

 

 

5.    Analysis and Comparison of the Alternatives

Based on the minimum and maximum data for each alternative is then determined non dimensional scaling as follow:

 

Combining attribute weight with the performance for each alternative, we calculate Weighted Score as follow:

6.    Select the Preferred Alternative

Based on Weighted Score, the preferred alternative is alternative (2) “Process using Decanter Centrifuge”.

7.    Performance Monitoring & Post Evaluation of Result

Comparison between the decision-making using non-compensatory and compensatory models show consistency. However compensatory models is preferred because it’s reduce level of subjectivity.

References:

1.    Sullivan, W.G., Wicks, E.M. & Koelling, C.P. (2012). Engineering Economic 15^th Edition: Chapter 14, p. 551-569

2.    Dhar. R. (1996). The Effect of Decision Strategy on Deciding to Defer Choice. Journal of Behavioral Decision Making, p. 265-281. Retrieved from http://faculty.som.yale.edu/ravidhar/documents/TheEffectofDecisionStrategyontheDecisiontoDeferChoice.pdf

3.   Straub, K. (2003). Decisions, decisions... What's a poor user (and designer) to do? Retrieved from http://www.humanfactors.com/downloads/oct03.asp