Hi!
My understanding of the terminologies in plain and simple english is: When you "benchmark", you COMPARE. When you "appraise", you ASSESS or EVALUATE.
Given the above definitions, the relationship between the two words seem to be wide apart.
In HR, maybe a link can be established. Maybe you can "benchmark" your Performance Appraisal System with others, either with companies or the appraisal tools per se.
When you are able to do this, then you are able to establish the relationship that you are looking for.
Seriously though, benchmarking is popularly used on "compensation" matters to determine your company's external competitiveness within your industry. This is usually done thru compensation surveys, either you join or simply buy available market data.
Appraisals are used to evaluate the performance of employees within specific periods and for specific purposes, e.g. regularization, promotion, bonuses, etc.
To me, a good performance appraisal is an evaluation of outputs/ outcomes versus agreed planned targets arising from a joint performance plan.
BEST wishes.
Ed Llarena, Jr.
Managing Partner
Emilla Consulting