Size estimation in e-learning

Measuring the size is first step to estimation. E-learning industry has developed its system of sizing using learning hours (seat time) with added parameter of complexity for each of the product types ILTs(instructor led trainings), WBTs(Web Based Trainings) and Online ( simple static web pages with little functionality) courses. However, with increasing complexity of learning systems employed by customers and the vast span of services offered by the e-learning organisations, one approach fit all does not work. For example, the learning hour approach works well if an ILT with standard work outputs needs to be developed. However, if the same ILT requires customisation as per customer templates with lot of programming effort going in, then the learning hour approach does not work because now the work goes beyond the normal ID (Instructional Design).
What is, therefore, needed is not one sizing model rather an approach which will yield measures comparable across business situations. E-learning can use the Opportunities for Error (OFE) estimation approach of Six Sigma for this purpose. In this approach, every aspect of course under development is broken down into the user experience from the perspective of where things may go wrong. For example, it will estimate the number of links that need to be coded in, number of pages that need to be built, number of words/lines that need to be scripted since each of these pose an OFE. The OFE sources can be different for each type of course and scope of work. However, what it does is that brings all the courses onto the same platform without seriously being biased to any particular type of work.