Twelve practical reasons for using batch management software
Have you ever asked yourself or your DCS vendor “Does it make sense for me to add a batch management package to my batch automation solution?” The answer to this question is not unqualified. This article identifies12 practical reasons why you may want to add batch management software to your batch automation solution.
ISA S88.01 defines a batch process as:
“A process that leads to the production of finite quantities of material by subjecting quantities of input materials to an ordered set of processing activities over a finite period of time using one or more pieces of equipment.”
The key elements of this definition are that:
Â· A batch process is discontinuous
Â· Each batch produces a predetermined amount of product
Â· The product and quantity of product is determined by the materials used, the process actions taken on the material, the order of the process actions, and the environment under which each process action is performed. A change to any of these factors impacts the final product produced.
A prerequisite for using batch management software is that you have a batch application. So, do you have a batch process? If yes, read on brave soul! If not, roll this article into a nice paper basketball and launch it towards your nearest circular file, and go take a nice nap.
So, you have a batch process
Now that we have established that you do have a batch process, to further determine whether or not your automation solution could use a batch management software component, reflect on the following questions:
1. Are those that support your batch automation solution readily available?
Without batch management software, the entire batch automation tasks must be configured in the controllers. This includes configuring equipment phase sequences (i.e., recipe building blocks), as well as the recipe sequences. A resource that is capable of configuring the controller, like a control engineer, is needed to perform these tasks.
With batch management software, equipment phase sequence configuration will still need to be created and/or modified by a resource that knows how to configure the controller. However the creation of master recipes can be achieved outside of the controller at the batch management software level by a userwho is process knowledgeable. This is usually a process engineer. The process engineer using tools provided by the batch management software creates master recipes by sequencing the building blocks created by the control engineer in the controller.
In most batch applications, the creation of master recipes is done more frequently than creating or modifying equipment phase sequences. Additionally, a process engineer is usually more available than a control engineer.
In choosing an appropriate batch management package for your application, you should consider the effort needed to make the recipe building block information created in the controller available to the batch management package and the ease of creating master recipes.
Batch management software should be considered for your automation solution, if you have limited access tothe resources that have the ability to configure your controllers.
2. How frequently do you create or modify master recipes?
With a batch management package, master recipes are created by linking pre-defined recipe building blocks, created in the controller, in the appropriate sequence needed to produce the product. To make recipe creation even easier, most batch management package also support the development of Operation libraries. An operation stored in an Operations library can be used in multiple master recipes; thus saving you time in creating master recipes. Some batch management packages even implement the Operations library in a manner that if a change is made to an operation in an Operations library, all instances of that operation used in master recipes are automatically updated with the changes.
You should also look for batch management packages where creating recipe procedures do not become a graphics adventure. The batch management package should automatically realign the recipe procedure display as recipe blocks are inserted into the procedure. You the user should not have to manually realign the display, a time consuming activity.
The more frequently you need to develop or modify master recipes the more likely you can benefit from adding a batch management package to your automation solution.
3. How large is your operator training budget?
Most, if not all, batch management software is built based on the S88.01 models and terminology. Operators who have a working knowledge of S88.01 should be able to readily interpret a runtime control recipe procedure display regardless of batch management package.
Where the different batch management software packages differ is in the color coding of the control recipe procedure blocks, and the permitted user actions through the batch runtime display. The color coding issue is easily resolved by selecting a batch management package that permits you to customize the control recipe procedure color schema. The permitted user actions issue is just as easily resolved by selecting a batch management package that enables you to customize the modes and states that you want your recipe procedures to support.
Batch management software should be considered for your automation solution if your plant has multiple batch processes and you have a limited budget or time for training operators to operateyour processes.
4. How frequently do you need to modify your batch equipment configuration?
Each time a physical change made to process, changes need to be made to the equipment logic in the controller. Without a batch management package it is more than likely that each sequence in the controller represents a complete recipe. As a result, each time a physical change is made to the process, all the affected sequences will need to identified and updated to reflect the changes. The issues each time are: will all the logic affected by the change be identified; and will the act of making the changes to each instance result in any undetected errors?
With a batch management package, if implemented properly, each physical change to the process affects only a single equipment phase in the controller. Making the appropriate change in the equipment phase automatically updates the logic used whenever the batch management package calls for the use of this equipment phase. Additionally, the modified equipment phase can be easily tested to ensure it functions as designed and documented for validation purposes. Retesting each master recipe in its entirety becomes unnecessary.
Batch management software should be considered for your automation solution, if your process frequently undergoes physical modifications.
5. How many master recipes do you need to maintain?
If you have only a few recipes and you do not expect to make many changes to them once they are implemented, you can probably do without a batch management package. In this scenario, the recipes will be hard coded in the controller. Any changes to the recipes will require personnel that have controller configuration know-how.
Most batch management packages provide tools for organizing recipes by status and state. This can be as simple as providing tools that enable a user to create folders for storing recipes. Each folder could represent a recipe state or status such asIn Development, Archived, Released-for-Test, and Released-For-Production. You can then move a recipe from folder to folder as the status of the recipe changes.
Batch management software should be considered for your automation solution, if you have a large number of recipes that you need to maintain and organize.
6. What are your batch monitoring and control needs?
Without a batch management package, you would create custom graphics to do this. However, each time a recipe procedure changes, the graphic displaying the recipe procedure would have to be updated to reflect the change. This includes changing the graphics and testing that the appropriate changes are made.
Most batch management software includes a standard dynamically updated interface that displays theexecuting procedure. Through this interface the user can interface with the batch. If changes are made to the master recipe procedure, this interface automatically updates to reflect the procedural change.
Batch management software should be considered for your automation solution, if you want to be able to monitor, and control the execution of batches from a graphical representation of the recipe procedure.
7. What are your batch data collection needs?
Without a batch management package, it is up to you to develop and implement for your solution the functions needed to collect, consolidate, and store batch related data.
Batch management packages usually have batch data collection capabilities built into the product. This includes collecting operator actions, batch and recipe procedure block status changes, batch equipment status changes and batch related alarms. Some batch packages enable you to define batch related continuous tags that are to be collected for batch as well as at when the data from these points are to be collected during the batch. Additionally few batch management packages also enable you to automatically consolidate batch related continuous datawith the batch datainto a single file. This saves you the time of having to incorporate in your report formats the logic for searching, extracting, and consolidating the relevant continuous and batch data from different databases at the time of report creation.
Having both batch data and batch related continuous data for each batch in a single file simplifies the process of archiving the data from a batch. When archiving a batch, you do not have to manually confirm that all the batch relate continuous data that is stored in a different database has been identified and will be stored with the appropriate batch. This is done for you automatically by the batch management package.
Batch management software should be considered for your automation solution, if you require extensive batch data collection.
8. What batch maintenance tools do you require?
Without a batch management package, you would need to develop, implement and maintain custom interfaces to perform this function. Most Distributed Control Systems (DCS) provide the tools that enable you to develop these interfaces using the HMI package that is integrated with the system. Additionally most DCS provide an application process interface (API) that provides the functions that you can use to develop custom interfaces using programs like Visual Basic and C++.
Most batch management packages provide as standard set of user interfaces formonitoring and controlling the status of batches from the time the batches are created to the time they are archived from the system. The standard interfaces may include interfaces for planningand sequencing batches, releasing batches to production and monitoring and controlling the status of batches that are active, completed, or aborted. An interface is usually also provided to archive batches off of the system.
Batch management software should be considered for your automation solution, if you need any elaborate batch maintenance tools.
9. How do you allocate processing equipment to a batch?
Without batch management software, you would have to develop, implement, and maintain the algorithms to perform this function.
Most batch management software packages provide you with the ability to manually allocate units to a batch at runtime time when the batch needs a unit, and to permit the batch management software package to automatically allocate an appropriate unit to a batch at the time the unit is needed by the batch is also available.
Batch management software should be considered for your automation solution, if you need the ability to dynamically allocate process units to batches.
10. Do you have the need to modify executing recipe procedures?
More than likely with all DCS there are standard faceplates provided for interfacing with sequences down in the controller. Through these interfaces, you will be able to control the execution of individual equipment phases. However, to manually change the execution sequences of phases or to control the execution of an entire batch, you will probably have to develop custom graphics to do this.
With most batch management software, the interface for interacting with control recipe procedures comes standard with the product.
Where the different batch management packages differ is in the functions provided by the interface and implementation of the interface. Some basic functions include runtime editing of phase parameters, re-running phases, skipping phases, setting phase breakpoints, aborting a phase/batch, putting a phase/batch into hold, and restarting a phase/batch.
Batch management software should be considered for your automation solution, if you need to modify the execution sequence of runtime recipe procedures.
11. What are your batch application security needs?
Most batch management packages provide the ability to tie into the security features already available with the DCS that the batch management package is integrated with. This capability results in each user having a single unique user ID/Password that identifies the applications including batch and application-functions that the user can access. Some batch management packages also enable you to require your system user to sign off on selected operator actions and batch events. Multiple user signoffs may be required. Each operator action and each batch event and associated signoffs are automatically recorded into batch history.
Batch management software should be considered for your automation solution, if you need to implement user security access protection on batch functions.
12. Do you need to make your batch data available to external packages?
An Application Process Interface (API) is usually available with batch management products enabling you to exchange batch related information between the batch management product and higher level production systems. When picking a batch management package you need to confirm that the provided interface provides the data exchange capability that your process requires. This may include the ability to import/export master recipes, pass batch planning information, pass runtime batch/phase information, and issue batch commands.
A batch management product maybe warranted if you need to make batch related data available for use in MES and ERP type packages.
There you have it; a dozen practical reasons why you may want to consider adding a batch management software package to your batch solution. I am sure you can think of others. The point is, the more practical reasons you have for needing a batch management software package, the more confident you should be that it is right thing for you to do.