To prevent plural users from unlimitedly activating the program by limiting the number of users capable of executing the program introduced to a work station.
The program 50 is not operated unless it is judged as operatable in an operation propriety judgement means 10. Then, a user information management means 30 judges that the execution of the program by the user requesting the execution of the program is possible for the execution request of the program 50 in the case that the number of the users while executing the program is smaller than the number of the users capable of simultaneously executing the program decided beforehand or in the case that the user requesting the execution of the program is already during the execution of the program. The operation propriety judgement means 10 continues the processing of the program in the case that the user information management means 30 judges that the execution of the program by the user requesting the execution of the program 50 is possible.