Michio Hoshikawa1 Hiroaki Sugita1 Kikuharu Arai2 Takashi Inoue3
Recently, standardization of procedural automation of manual operations has been promoted mainly by the International Society of Automation (ISA). As a leader in this area, Yokogawa released the operation efficiency improvement package, Exapilot, which integrates the expertise of skilled operators into automatic sequences and operational guidance for the first time in the world. Yokogawa has since gained much experience of many applications in various industries. To utilize Exapilot know-how to help customers operate their plants effectively, Yokogawa has launched a new service called "Best Practice Pilot." By applying it to a continuous polymerization process in the Ehime plant of NIPPON A&L INC., the project dramatically shortened the start-up time and reduced manual operations. This report outlines the Best Practice Pilot and its application to the polymerization process.
Recently, standardization of procedural automation of manual operations has been promoted mainly by the International Society of Automation (ISA), and the functional requirements necessary for automation are being studied by the ISA106 committee in the US.
As a leader in this area, Yokogawa released the Exapilot operation efficiency improvement package1, the procedural automation software in 2000, which integrates operational know-how into explicit knowledge and automatic sequences, for the first time in the world. Yokogawa has since provided more than 1,000 Exapilot systems around the world. The Best Practice Pilot is a service that offers customers a solution for the best plant operation by implementing the expertise of skilled operators into Exapilot procedures by utilizing know- how accumulated through the Exapilot applications.
This report introduces how Exapilot was utilized for operational improvement in the EHIME PLANT of NIPPON A&L INC.
The EHIME PLANT of NIPPON A&L INC. (hereinafter referred to as "Ehime plant") produces various types of plastic products. Especially, the polymer known as LITAC-A is much appreciated in the market because of its transparency, dimensional stability, and mechanical strength.
Some of the features of the continuous polymerization process to which this service was applied and its operations to be automated and standardized are described below.
These troublesome and delicate start-up operations placed a heavy burden on operators.
A few years ago, the Ehime plant consolidated several control rooms and migrated a distributed control system (DCS) from the old one to the CENTUM CS 3000. The consolidation was successfully finished but many operations continued to be done manually to replicate the operations equivalent to those before the consolidation. As a result, operational improvements to achieve the expected effects of the consolidation remained as future issues.
Around that time, Yokogawa was about to launch this service as one of its solution businesses, and the Ehime plant and Yokogawa shared various expectations. Consequently, we jointly studied the feasibility of applying this service as described below.
|Figure 1 Configuration screen of Exapilot|
An overview of the Best Practice Pilot and the Exapilot utilized for this service is described below.
Contents of the Service
In an unsteady state, and even in a steady state, many operations are left to the operators' discretion, posing an obstacle to the improvement of operation efficiency. The Best Practice Pilot offers consultation for procedural automation of manual operations and operation procedure standardization and implements the optimized procedures into Exapilot including its engineering service. The Best Practice Pilot includes the following.
Exapilot Operation Efficiency Improvement Package
|Figure 2 Execution monitoring screen of Exapilot|
The procedural automation of manual operations requires a lot of system resources and engineering man-hours if done using only DCS functions. Even after the completion, it entails considerable costs for maintenance in response to process changes, such as modification of equipment.
Exapilot provides icons on the configuration screen representing operational functions, such as starting pumps, FCS data setting, requesting field work, and holding a process until a predefined period of time has elapsed or a specific condition has been reached. By placing and linking these icons in a sequence of operation procedures on the screen, experienced operators can program their own expertise and procedures into Exapilot as semi-automatic operation sequences. The FCS data setting means downloading the settings of the data or mode of operation into the field control station (FCS). Figure 1 shows an example of the configuration screen of Exapilot.
As shown in Figure 2, execution of the programmed sequence is displayed on the operator console, which can be used for phase progress management.
Typical System Configuration
Figure 3 shows a typical system configuration for the automation of operation using Exapilot. Exaopc2 in this figure is OLE for Process Control (OPC) interface-compatible general-purpose OPC server software.
Figure 3 Example of connection with the CENTUM VP/CS 3000 system
For maintaining a certain service quality, each step of the procedure of this service is defined on the basis of the Six Sigma DMAIC (Define, Measure, Analyze, Improve, and Control), which is a famous quality control method for products. Table 1 shows the procedure.
Table 1 Procedure for the Best Practice Pilot
|Step 1: Define||
|Step 2: Measure||
|Step 3: Analyze||
|Step 4: Improve||
|Step 5: Control||
The application of this service in the Ehime plant is outli ned below.
The target operation was determined through discussion between the Ehime plant and Yokogawa. In the meeting, Yokogawa introduced examples of Exapilot applications and explained key success factors as know-how. Since this was the first trial of introducing an operational improvement service for the Ehime plant, the start-up operation of the continuous polymerization process was selected as the target of the service, since the procedure is sufficiently complex to expect certain benefits with limited risk of the work load for application configuration. The operation offering the maximum return was not selected because of its higher risk of considerable man-hours.
The improvement goals were to standardize the start-up operation, minimize the time required for the operation, and minimize manual operations (to almost zero, if possible).
Before starting the actual works, training of "operational improvement using Exapilot" was conducted at the Ehime plant to get the customer familiar with the service procedure. Since the targets were already set, the training was carried out effectively. A part of the operation procedures was temporarily input to Exapilot as a product of this training.
To establish the best operation procedure and to standardize it, the contents of the Standard Operation Procedure (SOP) for the targeted operation were assembled and modified to meet the actual best practice at the same time.
Through the training, people at the Ehime plant learned how to break down operation procedures into Exapilot and also learned how to construct logic using Exapilot.
The Ehime plant took the initiative in configuring the application. The configuration work included the following items.
This configuration work was finished in a total of approximately 10 working days over three months.
The improvement effect brought about by the service was evaluated and reported with the service activities of the application.
Based on the successful experience of Exapilot application, the Ehime plant is now considering expanding procedural automation to more complex operations as well as to other processes in the plant.
Yokogawa has conducted consulting services utilizing Exapilot tailored to each user's individual requests. Reviewing this case as the start of the service, Yokogawa will establish Best Practice for the service. This includes improving and enhancing the contents of the service, so that the service can be offered in a systematized way.
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