A hardware diagnostic system for use in relation to an industrial process, the system implementing a network comprising two or more sub-domains implemented as electronic instructions and/or data in one or more non-transitory computer-readable media, each sub-domain being or corresponding to a respective model representing at least part of the industrial process,
- wherein at least a first one of the sub-domains comprises first diagnostic information extracted by analysis of first object data, the first object data representing one or more first parameters measured in relation to a first set of product units that have been subjected nominally to the same industrial process as one another,
- wherein at least a second one of the sub-domains comprises second diagnostic information extracted by analysis of second object data, the second object data representing one or more second parameters measured in relation to a second set of product units that have been subjected nominally to the same industrial process as one another, and
- wherein the network further comprises at least one probabilistic connection from a first variable in the first sub-domain to a second variable in the second sub-domain, at least some information of, or used to extract the second diagnostic information being influenced probabilistically by at least some information of, or used to extract, the first diagnostic information.