How important to make an assessment at the end of training courses?

It is very important as it does not only refresh the overall training done for the day, it also indicates a better understanding of what was conducted and gives a better insight of understanding.

More importantly are the mini assessments that will occur during the course to allow your learners time to use their skills and then prepare them for the assessments at the end of teh course.  A good rule of thumb is what are the desired outcomes from the course and do they require an assessment to verify?  Usually the stakeholder will request some kind of assessment and if not the course is for information purposes.  I hope this helps 

it is important to make assessment at the end of tranning courses, To get feedback from trainees, that will benefit both trainees and on the training program, which helps develop the training process continuously.

training courses without an assesment is no training at all. 

Its very important.

Assessments reveal the effectiveness and relevance of the training. They also tell the Training team about the performace of the trainer, quality of content, mode of training. 

HR/Learing team can improvize, change and improve trainigs based on the assessment.