(675f) An Ontology Based Approach for Managing General Recipes in Batch Processe
AIChE Annual Meeting
Friday, November 17, 2006 - 2:10pm to 2:30pm
Recipe specifications constitute the most important block of information describing a batch process. Recipes provide the foundation used by several software applications that support process development and manufacturing, including simulation, safety analysis, recipe management, manufacturing execution systems. Over the past 10 years, two related standards have evolved to formally represent the recipe information: General Recipe and Master Recipe. A General Recipe expresses process requirements for various processing steps that are independent of equipment used, whereas a Master Recipe describes how to implement a specific batch of a given processing step on a specific piece of equipment. Master recipe has gained wider acceptance in the batch processing industry because it plays an important role in plant operation and batch process control. However, the development of general recipe standards is lacking even though it has the potential for providing a common framework that can be used by all stages in product lifecycle management. The lack of standards, in turn, leads to difficulties in information exchange between various tools and deriving the benefits provided by the tools.
A general recipe must capture for each processing step, information about operating conditions and material requirements, as well as logistics which is central to the execution of that step. In this paper, we provide a detailed discussion of the characteristics of batch processes which must be addressed in a general recipe representation. A review of the approaches which have been proposed so far, including Petri Nets or ad-hoc representations used in existing tools, has been provided. The current representation schemes have inherent limitations to accurately represent the wide range of recipe specifications that may arise in batch processes.
The proposed representation builds upon the concepts described in the general recipe standards (ANSI/ISA-88.03). New concepts have been added to represent flow of material between two operations, to allow conditional execution of operations in a unit procedure, to identify the operation that coordinates the decisions in execution of material flows. To provide an open, formal and systematic representation, we use ontology for defining the framework, and Web Ontology Language (OWL) for encoding the representation. A software tool has been developed for creating and managing the recipes. The methods for existing tools to adopt the representation, and developing new tools for batch processes based on the proposed representation are also discussed. We will demonstrate the proposed representation using a pharmaceutical process, and discuss how the proposed representation benefits batch process development and manufacturing.