I particularly like the pie calculation as it addresses more variables more effectively. I would add that the agreement used (probably an LLC or Limited Partnership rather than a corporation) should provide sufficient flexibility that when things change (and they certainly will) the agreement is ready to help adjust the relationships. Thus, I would, among other things, use the pie chart each year to help adjust the relationships to meet changes that have happened over the year. The prime example is the founder who left after six months to do something else. Or the manager who is brought in after the idea is making money, but not much money.