It is just like TOEFL, GMAT or SAT.
It sets the standards such as what it means to dress in "semi-formal" for a business meeting.
Currently if you train students, how do you test them? Would you ever fail your own students? IITTI offers you an independent, unbiased testing for your students; a validation of your competency in the eye of the market.
The IITTI standard sets the "what" to be delivered. It is up to each trainer to design the "how" to deliver it.
That is, your creativity and your brand can flourish from the "way" you deliver. Something uniquely yours.