To give suggestions on measuring the effectiveness of the development initiatives, you need to provide basic information like the nature of your industry, qualifications of these individuals, length of service of these individuals, the type of work they do, the type of work you want them to do in the future, their current performance level, and the gap in their performance, etc.
In addition to this, your development initiative should have the support of your organization's culture as well. What type of organizational culture do you have, and how did you measure it?
Next, consider the strategic plan of your company. Does the development initiative fall within the purview of the strategic plan?
Unless you provide complete information, it would not be prudent to suggest anything. In my last post, I had given generic information.
Thanks,
Dinesh Divekar