John wants to buy a tablet PC to use for his school assignment. John decides to evaluate the computers on four elements, and rates the importance of each element as follows: Element Importance Performance quality 30% Delivery speed 10% After-sales service 20% Cost 40% The campus store carries two different tablet PCs: Model A and Model B. Model A tablet has a relatively fast processor and a high-resolution screen, can be delivered in a week, includes around-the-clock technical support for a full year, and costs $800. The other model is a little slower and has lower screen resolution. However, it is available immediately, comes with a month of technical support, and costs $500. John uses this information to rate the performance of each offering with regard to the four elements on a scale from 1 (poor) to 5 (excellent) as

Value index for Model A = 3.1

Value Index for Model B = 3.4

Hence, John should select Model B because it has higher value index than model A.

Explanation:

Note: This question lacks necessary data of dimensions and its ratings. So, I have included the missing data from the internet.

Data Given:

Dimensions and its importance

1. Performance 30%

2. Delivery speed 10%

3. After Sales Service 20%

4. Cost 40%

Dimensions and Model Ratings

1. Performance      A = 4        B = 3

2. Delivery Speed A = 3        B = 5

3. After Sales Service  A = 4   B = 2

4. Cost                            A = 2    B = 4

Solution:

In this question we are asked to select the best model. And it can be done with the help of value index. So, first of we are obliged to calculate the value index for each of the model and respective dimension.

Value index for Model A:

Value Index = Summation of Dimension's Importance x Dimension's Rating

Value Index = (30% x 4) + (10% x 3) + (20% x 4) + (40% x 2)

Value index for Model A = 3.1

Similarly,

Value index for Model B =  (30% x 3) + (10% x 5) + (20% x 2) + (40% x 4)

Value Index for Model B = 3.4

Hence, John should select Model B because it has higher value index than model A.