Dear Piyaa Gautam,
You could have given little more information like the nature of your industry, your finished product or service, your designation, whether you handle the delivery or outsource the training to someone else, your method of TNA, type of programmes that you conduct, existing methods of measurement of ROI on training, challenges that you faced in measurement and so on.
Measurement of training effectiveness depends more on organisational research or research of your operations than the training itself. You should identify the costs associated your various business and measure the cost before the training and cost after the training. The reduction in cost is training effectiveness.
I have given exhaustive reply on the subject of training. You may click the following link:
https://www.citehr.com/523786-traini...ml#post2222367
In this reply, you will get further links. Go through all the links patiently and you will enhance understanding of the subject of training. Still if you have doubts then you may call me on my mobile.
Thanks,
Dinesh Divekar