Injecting More Procedural Control for Batch Production

July 2, 2015
Dow Chemical implemented a manufacturing execution system (MES) that increases repeatability of raw material deliveries for batch production and limits process upsets.

With more than 150 manufacturing sites around the world, pilot projects are standard practices for Dow Chemical. A recent pilot program at a specialty chemical plant was launched to test a new batch process strategy geared toward improving product repeatability and traceability, and reducing manual procedures.

Within the specialty chemical industry, material traceability starts in the warehouse and continues through multiple batch processes and eventually to the supply chain. High-level batch production can include enterprise resource planning (ERP) systems, manufacturing execution systems (MES) and production platforms continuously talking to each other.

However, the specialty chemical industry still relies on paper work orders for batch processing, and has been slow to digitize and adhere completely to ISA 88 standards. Recent industry data suggests that about half of all specialty chemical manufacturing batch processes are still paper-based batch instructions.

Dow Chemical felt a robust MES platform for batch production would greatly increase better repeatability, particularly for the entrance and exit of raw materials in the first batch processing station. Many of the manufacturer’s production facilities rely on small-capacity containers that look alike from the outside but hold different chemical makeups.

Misidentifying a container and adding the wrong raw material causes a process upset and moves the global chemical manufacturer further from its Six Sigma objective.

For this pilot project, Dow Chemical enlisted Burlington, Mass.-based Aspen Technology and its aspenOne MES suite to implement a new workflow process developed by the specialty chemical maker, called the high-integrity material flow (HIMF) system. The new system would authenticate all materials and generate orders to retrieve and load material into a process. To do this, Dow leaned on the MES’s production execution manager and the InfoPlus.21 historian to provide better traceability from the warehouse and during production.

“Our execution manager is aligned with ISA 88 and 95 standards. We provide a library of standard building blocks that we call basic phases,” says Robert Golightly, senior manager of marketing for Aspen Technology. “You can build it in a way that mimics your existing paper processes.”

Material success

With Dow’s new material flow system, connectivity between the MES platform and the warehouse data management system is essential for proper authentication of feedstock materials. The resource management function block within the MES suite drives the allocation of four resources: personnel, equipment, materials and process segments.

Once material moves from the warehouse, it travels to batch production, where an operator connects to the control system via a mobile HMI, a barcode scanner integrated with a wireless mobile computer.

A dispatching functionality executes work orders through various workstations and provides a full audit trail in the production chain. For Dow, the MES platform allows operators to define and manage different workstations within a production area. For example, operators can scroll a list of workstations and view configurations and process types supported at a given workstation.

The MES connects to the control system and allows the InfoPlus.21 historian to collect and store all batch process data, such as mixing, cooling, distillation, drying and more.

At the Dow pilot plant, the historian also interfaces with the plant control system to confirm the feedstock material at the first batch production station. The operator scans the material via the HMI and confirms recipe execution. The historian provides interoperable options to connect to PLC, SCADA or DCS platforms, such as open database connectivity and leveraging OPC technology.

Historian data is also available for mobile viewing at the specialty chemical plant through the use of HTML5 in the application software. Plant employees now can receive text and email notifications for specific batch production events. The customizable MES platform allows this global manufacturer to localize each installation.

Multi-site implementation

With the success of the pilot project, Dow Chemical is now rolling out this MES platform to all of its specialty chemical process plants. This huge platform implementation includes the usual hiring of engineering, procurement and construction (EPC) firms, and Dow is using Aspen’s Capital Cost Estimator to manage these multiple-site projects across the company’s portfolio.

“This new cost estimator tool is helping to achieve efficiency improvements by essentially breaking up large projects into smaller sub-projects, making them more manageable,” says Bruno Robitaille, project controller at Dow Chemical.

The ability to model large, multi-plant facilities as one integrated project is helping EPC companies provide Dow with yearly updates for capital materials and equipment pricing. “Dow has been able to significantly reduce the effort required to produce reliable project estimates even as the scope increases over time,” says Cameron Rezai, director of engineering solutions at Dow Chemical.

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