The approach that you have taken is traditional one. In this approach it becomes very difficult to measure the ROI on training. In this method the focus is on individual and not on the organisation. May it be noted that the focus of training should be on bringing organisational change.
In the recent past, I have given exhaustive reply on the subject. You may click the following link:
In the above link, there are lot of links further. Go through all the replies patiently and improve your understanding of the subject. It will take days for you to go through all the links and assimilate the contents of each link.
Whether to adopt the approach mentioned in my reply depends on your interest to measure the ROI on training. Not many Training or HR Managers have inclination to measure the ROI. Whether to join the bandwagon of that big lot or to stand apart, the choice is yours!
From the list of businesses that you have given, your training effectiveness lies in the following:
a) Telecom Operations & Maintenance: - Reduction in cost of operations and reduction in cost of maintenance because of the training.
b) Sales & marketing for Batteries : - Reduction in sales cost and reduction in marketing cost because of the training. Further you need to measure inventory carrying cost of batteries before the training and after the training.
You need to measure for each business vertical the primary and secondary costs. In fact in the above two examples, I doubt whether anyone has taken any trouble to measure these costs. If not, then your first training programme should be on how to measure these costs scientifically. Inaccurate measurement will give you the inaccurate results.
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15th April 2015 From India, Bangalore