My code

for each role define parts percent in the body and cost. totalPercent is the max amount of a room energy it will use
    parts: {
        pieces:[
            {typeName:WORK, percent:0.5, cost:100},
            {typeName:CARRY, percent:0.25, cost:50},
            {typeName:MOVE, percent:0.25, cost:50}
        ],
        totalPercent:0.67
    },

then you just have to go through parts.pieces the amount of each part is percent * energyRoom * totalpercent /cost

And then loop pushing each typeName in an array