These four are inter linked. The knowledge gained one source can be useful to the other components.
The better percentage to be adopted is Teaching 40%, Research 30%, Consultancy 10% and Extension 20%.
While in teaching besides our self acquired subject matter, we can also get feedback from students. In Research and Extension we know the field situation which will help in Consultancy.
The combination may be like this, T+R+E: 90%, R+E+C:60% and R+C: 40%. All these adopting depend ends upon the individual attitude and aptitude of the persons who practices
'Should' is a strong word I think. What happens if the college teacher is a good teacher but a weak researcher? Does it make sense to have specific proportions that 'should' be adhered to? If you insist that a good teacher but a poor researcher undertakes research what quality of research are you hoping they'll produce or is it simply going to become a 'box ticking' exercise? Ultimately I'd assume that these proportions would be set within a given institution and those choosing to work there would accept them on taking up employment.
Of course, percentages for the activities of a college teacher differs per the needs of the person in question. However, the core duty of a teacher in a college is to impart content knowledge via teaching. Research is paramount today because it is the breakthrough for societies to cope with their challenges and a college teacher must be excellent in undertaking research to assist students mimick their examples. The co-curricular activities like extension and consultancy are very important because they aid in addressing the unique perplexing conditions that can be great obstacles for realizing learning outcomes in students. It offers a platform for college teachers to answer and guide students to make wise decisions about their educational and career goals.
I think the percentages for these activities must depend on the time of the academic calendar. When school is in session, more teaching and consultancy activities (60%) but during vacations, more research activities (80%). That is how I balance my schedule so that I can effectively undertake my responsibilities as a college teacher without compromising on any of them. It has been working effectively for me.
I think research is the main activity of a college/University teacher whilst a teacher will teach his/her students on the basis of research around. So Research should be 80%, teaching 10% Consultancy and Extension activities 10%
In my opinion, it should be 50, 50 because research and consultancy contributes a lot in effective teaching. The teacher becomes very updated for knowing what is going on in the field or in the industry.
It used to depend on what the individual institution's requirements were for tenure. The main job of a college professor is teaching, it seems to me. Then you need to consult when asked, continue with active research, do community outreach, be on committees within and outside the institution, and even, in the case of speech pathology, engage in intervention practices. Its very difficult to assign a number to these, yet teaching must be at least 50% of your time, which includes student mentoring.