W3_BUD_Multiattributes Decision Making (Non Compensatory Models)

1.   Problem Definition

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

The acceptable limits for each cleaning method describe as follows:

Attribute	Maximum Acceptable Value
Cost (US$)	60,000
Time (calendar days)	21

Ordinal Ranking

Paired Comparisons	Rank
·   Cost > Safety ·   Cost > Environmental ·   Cost > Time ·   Safety > Environmental ·   Safety > Time ·   Time > Environmental	1.    Cost 2.    Safety Issue 3.    Time 4.    Environmental Impact

 

5.    Analysis and Comparison of the Alternatives

Satisficing

Comparison of each cleaning and sludge processing method shows that alternative (1) “Direct to Container” is not acceptable because the cost exceeded the maximum acceptable cost.

Attribute	Maximum Acceptable Value	Unacceptable Alternative
Cost (US$)	60,000	(1) Direct to Container
Time (calendar days)	21	None

Lexicography

Lexicography select preferred alternative based on top rank attribute (Cost). The other’s attributes only used when the top rank attribute fail to give single preferred alternatives.

Attribute	Rank	Alternative Rank
Cost	1	Alternative (2) > Alternative (3)
Safety Issue	2	Alternative (3) > Alternative (2)
Time	3	Alternative (2) > Alternative (3)
Environmental Impact	4	Alternative (2) > Alternative (3)

 

6.    Select the Preferred Alternative

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

7.    Performance Monitoring & Post Evaluation of Result

To ensure the accuracy of decision-making by Non Compensatory Model, it will be compared with the Compensatory model addressed for W4 blog posting.

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.    Houy, N. & Tadenuma, K. (2009). Lexicographic Compositions of Multiple Criteria for Decision Making. Journal of Economic Theory. p. 1770-1782