In this paper a discrete-continuous project scheduling problem is considered. In this problem activities simultaneously require discrete and continuous resources. The processing rate of each activity depends on the amount of the continuous resource allotted to this activity at a time. All the...

The Liu-Layland periodic scheduling problem can be solved by the house monotone quota methods of apportionment. This paper shows that staying within the quota is necessary for any apportionment divisor method to solve this problem. As a consequence no divisor method, or equivalently no...