First let me clarify about KRAs. These are developed to measure the business performance in general and individual or department's performance in particular. KRAs are never designed to measure skill sets, declared or undeclared ones. Requirement of specific skills is mentioned in Job Description (JD) and not in KRAs.
Coaching is one of the important secondary duties of a manager. Manager is supposed to conduct coaching classes for his/her juniors to build requisite skills. HR may train managers on coaching skills.
Take the case of Purchase Manager. He/she may have KRA as "Reduction in Inventory Carrying Cost of Raw Materials by ___% by ____ (date)". Purchase Manager cannot attain this KRA on his/her own. He/she needs support from his/her juniors. This is where coaching comes in picture. Unless Purchase Manager coaches his/her juniors on vendor development activities, procurement negotiations, this KRA can never be attained.
One more clarification is required and it is on mentoring. In "Formal Mentoring Programme", efforts are made to build overall personality of mentee. Mentor may help mentee in designing his/her career plan. Mentor's job is to interpret organisation's philosophy, values etc and thereby improve affiliation or engagement of mentee to the organisation. It is not mentor's job to build specific skills.
1st December 2015 From India, Bangalore