  This paper takes a game theoretical approach to open shop scheduling problems
with unit execution times to minimize the sum of completion times. By supposing
an initial schedule and associating each job (consisting in a number of
operations) to a different player, we can construct a cooperative TU-game
associated with any open shop scheduling problem. We assign to each coalition
the maximal cost savings it can obtain through admissible rearrangements of
jobs' operations. By providing a core allocation, we show that the associated
games are balanced. Finally, we relax the definition of admissible
rearrangements for a coalition to study to what extend balancedness still
holds.
