Validating Operating Manual by Reasoning about State Transitions Through System’s Function Models

In complex process systems such as oil and gas plants, operating manuals are crucial to ensure suitable operator response to both regular and emergent events. Validation is accordingly essential to guarantee usability and correctness of manuals. Most of validation methods, however, only focus on the final goal of manual execution in quantitative perspective and fail to validate whether actions are arranged reasonably and safely. This paper proposes an approach for validating intentions of steps in an operating manual on bringing about state transitions of system’s functions described by Multilevel Flow Modeling (MFM). By defining phases of functions and specifying rules for reasoning about state transition and propagation, the knowledge about how individual functions should transit their states sequentially can be derived from an MFM model. The operating manual can thus be validated by confirming consistency between the derived sequence and actual state transitions resulting from executing different component actions. The proposed approach is applied to validate an operating procedure that handles a gas treatment process. The same kind of knowledge about state transition provided by MFM are also expected to be useful for aiding operators in maintenance of their situation awareness during a manual performance.