Enterprise software with half-duplex interoperations

In [3] the author and his colleague Dampney showed how a new solutionto view update problems based on a category theory can be used to supportenterprise information system interoperation. We now have considerable experiencein applying that technique in industry. One of the major applications has been todeveloping interoperations between large databases. The view update approach tointeroperations provides reasonable functionality while limiting the modificationsneeded to implement it. However, for mathematical reasons the view update approachto interoperations requires a significant amount of attribute harmonisationwhich means that companies must share data that they sometimes view as confidential.In testing this approach it has become apparent that, like full-duplex communications,it guarantees interoperations in both directions between the cooperatingdatabases. However, in the systems tested interoperations were frequently necessaryin one direction only for particular actions (inserts or deletes) on particular entities.This paper introduces a “half-duplex” approach to designing interoperationsbetween extant systems in which data flows both ways between the systems, buton any action on any particular entity it will only flow one way. This significantlyextends the domain of application of the technique by avoiding the former need toshare information which some organisations insisted on keeping confidential.