S88 is a standard addressing batch process control. The standard defines hierarchical recipe management and process segmentation frameworks which de-link products from the processes that produce them. S88 as a standard encompasses software, equipment and procedures. But it goes beyond these elements: it is a design philosophy, a way of thinking; it was formulated to address the following issues facing batch control:

  • Lack of a universal model for batch control.
  • Batch processing requirement communication difficulties experienced by users.
  • Integration of solutions from different OEMS and SI’s.
  • Batch control solutions configuration difficulties.

What were the direct benefits touted by the S88 standard?

For starters the standard would lead to improved process design, ease recipe development, improved identification of customer needs and significantly reduced time-spans for achieving full production levels with a new system or for each new product. The S88 standard promised improved operation reliability, reduced automation life cycle cost of batch processes including lowering initial automation costs.

The S88 standard can broadly be looked at in terms of three elements: recipes, equipment and control. We can also define three broad guiding principles.

1)   The first principle is that of assigning specific meaning to control. The standard states that control must occur but how that happens doesn’t matter.

2)  The second principle is the separation of recipes from equipment. Recipes and equipment are considered two very different activities and should not be thought of as one.

3)   The third principle is the segmentation or modularization of processes.

The first element of the standard: a recipe, defines a particular sequence of equipment action. The standard defines four types of recipes (general, site, master and control) that focus on varying levels of specific information that target different parts of a company. The standard defines two models for defining recipe procedures: the process model and the procedural control model.  The former focuses on describing process functionality over equipment and targets general and site recipes. The latter focuses on describing the process as it relates to physical equipment, and consists of a hierarchical set of ordered elements with a procedure, the highest element in the model, consisting of an ordered set of unit procedures which consist of and ordered set of process operation which consist of an ordered set of phases.

The second element of the standard: equipment is modularized using the physical model into seven levels: enterprise, site/plant, areas, process cell, unit, equipment modules and control modules. Some of these levels may be excluded, but not the unit, which is considered the nexus of batching activities.

The last element of the standard:  control is the most basic element of the physical model and is typically a collection of sensors, actuators, other control modules and associated process equipment that is operated as a single entity.  Control modules are given commands, drive equipment to a state and are capable of providing information. The S88 standard also defined an equipment module, which groups physical devices for performing one or more specific functions and can include one or more control modules.

The control and equipment module combine together with other equipment to form units to provide functionality needed to execute a process. Recipes are linked to equipment control using procedural control (recall the procedural control model) element of procedure, which describes the actions necessary to make equipment perform actions. The instructions in a recipe are conveyed to the control equipment through linkage at the phase level of the control recipe procedure.

The S88 standard for batch process automation has been elaborated above. Does the standard measure up to the hype its proponents propagate? The benefits, outlined below, seem to suggest the standard more than measures up in many aspect of batch process control.

  • Reduced time to market of new products: modular approach emphasized by the standard eases shift from one recipe and control to another.
  • Consistency across processes and plants: shared modules and recipes which are decoupled from particular equipments means they can be deployed on a variety of equipments and controls.
  •  Improved quality: the standard enables tracking and tracing and provides more detailed and real-time information increasing product consistency.
  • Easier maintenance: s88 promotes isolation of recipes from equipment. It also emphasizes modularization. These factors when combined lead to quicker and easier troubleshooting of problems.
  •  Greater equipment utilization: isolation of recipes and equipment results in lesser time to modify a recipe. Duplicating parts of a process to make a new process reduces the setup time for equipment.S88 increased throughput by reducing product launch times and reducing down times during equipment use.

Weigh Label, along with their integration partners have implemented a variety of S88 standard and compliant automated batching systems across a variety of industries; food and pharmaceutical. We are ready to work with you at any stage within your project, from the design phase straight through to completing a project left by others.

Contact us today to discuss your project. See for yourself how our experience and approach may help you deliver your project.