The variable resource option works in conjunction with the AND command as well as the Min Max commands. It is used to tie in multiple resources to a single operation but at potentially separate times. For example, suppose you want to apply 3 resources to a single operation but the 3 resources do not need to be working on the operation at the exact same time. If the variable is checked the three resources would be used when available and DMS would not have to ensure the resources availability at the exact same time. When used with the Min Max feature you may have an operation that requires at least 1 welder but you could potentially apply up to 4 welders if they become available in the timeframe of when the operation is running. The welders do not need to all be available at the same time. You would use a Min value of 1 and a Max value of 4 and check the Variable Resource option.