In my experience, the most satisfied anyone is with a job is on the first day and it gradually dissipates over time. Therefore, perhaps employees should start with 100% satisfaction and have it go down from there if needs are not met in a timely manner. In fact, perhaps it should just go down anyway. Maybe 1% per week or something like that. Then when a demand is met you get a temporary boost for a period of time before it starts going down again. You could set a floor of 75% (or similar) that it will not drop below as long as all demands are met.