Hi You could use the hackman and Oldhams Job Charectoristic Model. They have a theory and a resultant formula to measure motivation.
as given below.
Please look it up
Motivating Potential Score (MPS)
Using the five core job dimensions, you can score each job by its potential to motivate people. This is shown by the equation below:
MPS=(skill variety+Task Identity +Task Significance) X Autonomy X Feedback
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Diveded by 3
From this equation, we can see that autonomy and feedback carry more weight than any of the first three job dimensions. For instance, a job can be low on skill variety and still have a reasonable MPS if autonomy or feedback are high. A job that's low on either autonomy or feedback, though, will be scored significantly lower.
There are other measures too such as the Herzberg Hygiene and Motivating factors etc
A psychomeric test has to be used (preferably constructed) for the company and then measures taken
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