Question

-what are the methods of evaluating the layouts ?and diffrence between them

-what is meant by analytical hierarchy process used in systematic layout planning evaluation ?how and when to use it?

-what is numerical scoring mehods to evaluate the block lay out in the systematic layout planning ? how and when to use it?

Answer 1

Ans 1) The methods used in evaluating the layouts are as follows:

• Factor Analysis
• Simple Additive Weightage (SAW)
• Weighted Product Method (WPM)
• TOPSIS
• Analytical Hierarchy Process

These are known as MADM Methods.

1) Factor Analysis: In this method, qualitative ratings with values are given on four parameters only i.e.

Ratings	Values
A(Almost Perfect)	4
E(Especially Good)	3
I(Important Results)	2
O (Ordinary Results)	1

The option/alternative with highest score is ranked first and so on.

2)Simple Additive Weightage: It is also called as Weighted Sum Method and one of the simplest MADM method. Under this method each attribute is given a weight, and the sum of all weights must be 1. Each alternative is assessed with regard to every attribute. SAW can be used for any number of criteria if all the elements of the decision table are normalized.

3)Weighted Product Method : This method is same as  to SAW and the only difference is multiplication instead of addition in the model . The normalized values are calculated similar to SAW method. Each normalized value of an alternative with respect to an attribute, is raised to the power of the relative weight of the corresponding attribute.

4) TOPSIS method :It is based on the concept that the chosen alternative should have the shortest Euclidean distance from the ideal solution, and the farthest from the negative ideal solution. The ideal solution is a hypothetical solution for which all attribute values correspond to the maximum attribute values in the database comprising the satisfying solutions; the negative ideal solution is the hypothetical solution for which all attribute values correspond to the minimum attribute values in the database.

(5) Analytical Hierarchy Process : It is based on the well- defined mathematical structure of consistent matrices and their associated eigenvector’s ability to generate true or approximate weights.

Ans 2) Analytical Hierarchy Process is one of the most widely used multiple criteria decision-making tools. The AHP methodology compares criteria, or alternatives with respect to a criterion, in a natural, pair wise mode. To do so, the AHP uses a fundamental scale of absolute numbers that has been proven in practice and validated by physical and decision problem experiments. It converts individual preferences into ratio scale weights that can be combined into a linear additive weight for each alternative. The resultant can be used to compare and rank the alternatives and, hence, assist the decision maker in making a choice.

Ans 3) Block layout represents the sizes of departments in the building. In the plant layout they should be planned very efficiently in order to maintain the plant flexibility and the scope of working in the plant for long run.

Systematic layout planning is an organized way to conduct layout planning, it consists of a framework of phases, a pattern of procedures and a set of conventions for identifying , rating and visualizing the elements and areas involved in a plan.

Numeric Scoring Methods is used to give scores to the plant layout according to their design, specification, and working environment .Firstly they are useful where benefits are difficult to quantify objectively; secondly, they can be used to aggregate the results of multiple appraisal methods to provide an overall comparison.

So, numeric score methods is to give scores to the different sizes of the department so that seeing the rating the systematic layout planning can be done.