This paper proposes a new approach to the well-known Liu–Layland periodic scheduling problem. This approach proves that any just-in-time sequence with maximum absolute deviation being less than one is in fact a periodic schedule. Consequently, periodic schedules can be obtained by any algorithm capable of generating just-in-time sequences with maximum absolute deviation being less than one, for instance, any algorithm minimizing maximum deviation or the quota methods of apportionment.
Key Words just-in-time sequencing - periodic scheduling - the Liu–Layland problem - hard real-time systems - apportionment problem