An inter-agent interaction anomaly management method for a multi-agent system supporting inter-agent interactions in a distributed computing environment, the multi-agent system comprising means for running a plurality of application agent groups (5a,5b,5c), each application agent group (5a,5b,5c) comprising one or more application agent computer programs (6,7,8), and means for running one or more administrative agents computer programs, each administrative agent computer program comprising code means arranged to assign one or more anomaly management agent computer programs (3a,3b) to each application agent group (5a,5b,5c) of said multi-agent system and code means arranged to reassign surplus anomaly management agent computer programs (3a,3b) to any one of the plurality of application agent groups (5a,5b,5c) if the number of anomaly management agent computer programs (3a,3b) serving a number of application agent computer programs (6,7,8) for that application agent group (5a,5b,5c) is greater than a value of a load index, wherein the load index indicates a predetermined ratio of the number of anomaly management agent computer programs (3a,3b) to the number of application agent computer programs (6,7,8), the inter-agent interaction anomaly management method comprises a referring application agent computer program performing the steps of: participating or seeking to participate in an interaction with a referred application agent computer program; determining that an interaction anomaly has occurred if the interaction with said referred agent computer program did not proceed in accordance with the expectations of the referring agent computer program; determining if a condition related to the referred agent computer program has caused said interaction anomaly in the interaction by: communicating with one or more agent description directories (12,13) which maintain the association between the referred agent with one or more anomaly management agent computer programs (3a,3b) to determine which one or more of said anomaly management agent computer programs (3a,3b) should receive a report message; generating the report message which contains information related to the interaction anomaly and enabling the referred agent computer program to be identified by an anomaly management agent computer program (3a, 3b); and referring the referred agent computer program by sending the report message to at least one receiving anomaly management agent computer program (3a, 3b) associated with the agent group of the referred agent computer program, whereby the information provided by the report is processed by a receiving anomaly management agent computer program to determine if at least one condition affecting the referred agent computer program has caused the interaction anomaly. participating or seeking to participate in an interaction with a referred application agent computer program; determining that an interaction anomaly has occurred if the interaction with said referred agent computer program did not proceed in accordance with the expectations of the referring agent computer program; determining if a condition related to the referred agent computer program has caused said interaction anomaly in the interaction by: communicating with one or more agent description directories (12,13) communicating with one or more agent description directories (12,13) which maintain the association between the referred agent with one or more anomaly management agent computer programs (3a,3b) to determine which one or more of said anomaly management agent computer programs (3a,3b) should receive a report message; generating the report message which contains information related to the interaction anomaly and enabling the referred agent computer program to be identified by an anomaly management agent computer program (3a, 3b); and referring the referred agent computer program by sending the report message to at least one receiving anomaly management agent computer program (3a, 3b) associated with the agent group of the referred agent computer program, whereby the information provided by the report is processed by a receiving anomaly management agent computer program to determine if at least one condition affecting the referred agent computer program has caused the interaction anomaly. generating the report message which contains information related to the interaction anomaly and enabling the referred agent computer program to be identified by an anomaly management agent computer program (3a, 3b); and referring the referred agent computer program by sending the report message to at least one receiving anomaly management agent computer program (3a, 3b) associated with the agent group of the referred agent computer program, whereby the information provided by the report is processed by a receiving anomaly management agent computer program to determine if at least one condition affecting the referred agent computer program has caused the interaction anomaly.