To provide a service coordinator by controlling the execution of transactions and to satisfy the inter-transaction limit condition that is designated for every composite transaction when the execution requests are given to plural services and a group of processing (composite transaction) is carried out as a whole.

Plural coordinators a 130 set on a network 100 are expressed in a pair of a set of transactions designated to services 140 to 142 and a set of inter-transaction limit conditions. Then the execution of the transaction set is controlled to satisfy the limit condition set. Thus, a coordinator 130 is obtained with no dependence on the services 140 to 142 and accordingly can be offered as a general-purpose service in the network 100. Furthermore, the concentration of load can be evaded because a coordinator factory 120 produces the coordinators 130 for every composite transaction.