Evaluations

Must, should and can criteria

One way of prioritising criteria is to differentiate between must, should and can criteria:

Must requirement: fulfilment of this requirement is mandatory. Without it, the service makes no sense.
Target requirement: The fulfilment of this requirement is important
Optional requirement: The fulfilment of this requirement is desirable, but has no influence on whether the service is used.

Decision matrix

A decision matrix helps when there are several alternatives for solving a problem. The alternative solutions are evaluated on the basis of meaningful criteria. A decision matrix can be weighted or unweighted. In a weighted matrix, the criteria are multiplied by certain factors to express their relative importance. The procedure for this method comprises the following steps:

The question is defined.
The alternatives are shown.
The criteria are determined.
The weighting factors are defined (optional).
The criteria are evaluated.
The variant with the most points is favoured.

Below is an example of a weighted evaluation matrix with the weighting factors 1 (completely unimportant) to 5 points (very important) and the evaluation factors 1 (very poor) to 10 (very good).

Decision
Should I no longer run my applications in my own data centre but in a cloud?
		Use cloud services		Use your own data centre
Criteria	Weighting	Rating	Total criteria	Evaluation	Sum of criteria
Scalability	5	8	40	5	25
Simplicity	4	5	20	10	40
Cost saving	3	8	24	6	18
Dependency set	4	5	20	8	32
Internet access	5	10	50	5	25
Data security	1	10	10	1	1
Total variant			164		141

In this example, the „Use cloud services“ variant is preferable.