Contents of S88 Part 1
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The standard include the following sections



1 Scope

Short explanation of the purpose

2 Normative references

Refers to :

IEC 848: 1988, Preparation of function charts for control systems (SFC's)

IEC 902: 1987, Industrial-process measurement and control .

3 Definitions

Provides a list of definitions that describe the terminology - the meaning of 63 words and phrases from Allocation to Unit Procedure. This tutorial includes a few of the more relevant definitions and more importantly uses the terminology.

4 Batch processes and equipment

Introduces the sub topics

4.1 Processes, batches, and batch processes

Describes what A process is  - a sequence of chemical, physical or biological activities for the conversion, transport or storage of material or energy.

Briefly mentions continuous and discrete parts manufacturing, and batch. type processes then points out that the standard only covers Batch processes

(But see Can S88.01 be used for continuous or discrete processes?)

And introduces The Process Model.

4.2 Physical model

Describes and introduces The Physical Model

Points out that the four lower equipment levels (process cells, units, equipment modules, and control modules) are defined by engineering - see S88 Modularisation for more information.

4.3 Process cell classification

Discusses the classification of process cells by the number of different products manufactured and by the structure of the equipment used .

Describes single path, multiple path, and network topologies.

5 Batch control concepts

Discusses batch control concepts, introduces the concept of recipes.

5.1 Structure for batch control

Describes Basic Control, Procedural Control and Coordination control, the three types of control needed for batch manufacturing.

5.2 Equipment entities

Discusses the equipment entities that are formed from the combination of equipment control and physical equipment, and the general relationship between the procedural control model, the physical model, and the process model.

5.3 Recipes

Discusses the four types of recipes, the five categories of information contained in a recipe and how this information changes for the different recipe types, and the relationship of the control recipe procedure to the equipment procedure.

5.4 Production plans and schedules

Production plans and schedules describe the production requirements for the enterprise, sites, areas, and process cells.

Details discussion of the various types is outside the scope of the, but it does go on to describe what such schedules contain especially as applied to process cells.

5.5 Production information

This section discusses information generated in during production.

It mentions how this applies to higher levels of the organisation and how summary information may be all that is needed at higher levels

At the process cell level where the batches are actually executed, individual batch records are generated

This  may include a copy of the control recipe that was used to make the batch, actual process data that corresponds exactly to the recipe formula,

such as the amount and type of material charged and data whose collection is specified by the recipe such as utilities consumption, Operator comments and Analysis data. All recorded information pertaining to a batch is referred to as the batch history.

5.6 Allocation and arbitration

Discusses allocating resources to a batch or unit and arbitrating the use of common resources when more than one requester needs to use it at the same time.

Resources such as equipment are assigned to a batch or a unit as they are needed to complete or to continue required processing.

Allocation makes these assignments.

An algorithm such as "first come/first served" might be used as a basis for arbitration.

5.7 Modes and states

Discusses the modes and states of equipment entities and of procedural elements.

The status of equipment entities and of procedural elements may be described by their modes and states.

Modes specify the manner in which these transitions take place; states specify their current status.

Establishes an 'Example' State transition diagram for procedural elements.

Note - this is discussed in this tutorial in Interfacing procedural elements.

5.8 Exception handling

Points out that exceptions (An event which occurs outside the normal or desired behavior of batch control) can occur at all of the levels in the control

activity model and may be part of procedural, basic, and coordination control.

But provides no guidance on how to handle them.

6 Batch control activities and functions

Discusses the control activities Recipe Management, Production Planning and Scheduling,Production Information Management, Process Management, Unit Supervision, Process Control, and Personnel and Environmental Protection.

Elaborates on the control tasks defined in Section 5.1 for the equipment entities discussed in Section 5.2, which are the bottom four levels of the Physical Model

6.1 Control activities

Identifies seven control activities, as represented in the Control Activity Model

6.2 Recipe management

Describes the control functions that create, store, and maintain general, site, and master recipes.

Also explains master recipe procedural elements functionality that creates, maintains and makes available for subsequent use, the procedural elements used in master recipe procedures. These become the building blocks of the master recipe procedure.

Note - these are a key to making a good implementation that allows the recipe developer to create all the recipes they need but without having to program or understand the controllers.

6.3 Production planning and scheduling

The decision process associated with producing a batch schedule (using the master recipes) that is provided to Process Management.

6.4 Production information management

Discusses collecting, storing, processing, and reporting production information, both batch and non batch related.

6.5 Process management

This extensive section describes control functions that manage all batches and resources within a process cell, and pulls everything together.

Note - most (or some, perhaps enough!) of this should come as standard with a batch manager product. Be aware of what standard capabilities there are and what is involved setting them up. And what is needed to meet requirements that are outside their scope.

6.6 Unit supervision

Describes control activities that ties the recipe to equipment control via Process Control

6.7 Process control

The control activity encompasses (equipment) procedural and basic control, including sequential, regulatory,

and discrete control, in addition to gathering and displaying data.

Process Control is discussed in terms of three control functions: execute equipment phases,execute basic control, and collect data

6.8 Personnel and environmental protection

Is included in the control activity model to emphasize the importance of protection systems and to indicate the point in the model

appropriate for insertion of a separate protection system of this type. A complete discussion is beyond the scope of the standard.