Hi Shammi Nanda. At HolacracyOne, we have people at different levels of time commitment, which we assess in percentage. Basically, sometime full time is at 100%, someone working 4 days/week is at 80%, etc.
We decide the compensation level based on our badge system — basically a system where people can earn "badges" for the skills they contribute. Some skills are more valuable than others, and different set of badges have different levels of compensation.
Then if someone is part-time at 80%, they will earn only 80% of the target compensation that their badges can earn.
This only for "work contribution", or what would equate to a salary. The founder is compensated under the same system, without extra for being the founder. However, the founder (and others) have shares of the company, for which they earn "dividends" too.
Hope that helps a bit. Note that the badge system I'm mentioning could be replaced with a simpler approach — my main point was that we determine compensation regardless of time commitment, then we apply the time commitment percentage to that result.