Kiesel Bauchemie GmbH u. Co. KG, Esslingen/Germany - Case Study: Process control system with integrated materials management

Minimizing capital tied up in stocks of raw materials in the process industry

The tying up of unnecessarily large amounts of money in inventories is commonplace and it is not only the automotive industry that has learned from this. It is also a recognized problem in the process industries, as both continuous and batch production lines demand the uninterrupted provision of raw materials. Therefore, materials management needs to be linked to the process, as only then can real-time needs-optimized provisioning be achieved for process technology. This makes possible a process control system that has materials management consolidated in its functional range, namely ProLeit’s Plant iT. The results that can be achieved thereby are shown by the example of modern construction chemicals production. With the help of Plant iT, stored supplies of the majority of raw materials at Kiesel Bauchemie can be reduced and in part on a day-to-day basis.

Operational excellence is the systematic improvement of performance with a clear focus on increasing value. Sustainable improvements are generally achieved through reductions in costs and particularly through reductions in tied-up capital, but also by increasing turnover and customer satisfaction. The reduction of tied-up capital represents a key variable for process industries in relation to operational excellence, as millions of Euros are as before stored as a precaution in silos and tank farms, in order to be able to satisfy the demands of process control.

The critical issue is the previously available threshold between the process control level and the ERP (Enterprise Resource Planning) level: the material conversion processes have only one time-delayed information flow into the material management modules of the ERP systems, such as SAP or Charisma. This barrier to operational excellence in process technology is eliminated by the utilization of the Plant iT modular software system, for materials management is an integral part of the process control system.

Modular design and open architecture
20 years of experience of software development and of numerous applications in various sectors have gone into this process control system. The Plant iT modules comprise of:

• The Plant Direct iT process control system;
• The Plant Liqui iT technology-oriented recipe control;
• The Plant Batch iT batch system;
• The Plant Acquis iT production data management system;
• The MES functions of Plant Trace iT; and
• The parameterizable link to ERP (Enterprise Resource Planning) software such as SAP R/3 or Charisma.

All system modules have a central engineering environment with a consolidated data pool and an integrated interface for parameterization. All system and configuration data can be accessed in this environment via a directory structure similar to that of Windows® Explorer. User administration, message profiles, pools of graphical elements for visualization, etc. are accessible in this way as is the complete plant structure right down to the individual actuators and sensors that can be parameterized using cascaded location keys. Even entire sequences within processes can be parameterized to the greatest possible extent, so that programming is largely replaced by parameterization.

Plant Batch iT, the high-performance system for recipe and job management, was developed for the specific requirements of recipe-controlled batch processes, as they are used at Kiesel GmbH & Co KG. Plant, process and recipe modeling takes place either in strict conformance with ISA S88 or simplified models derived from it. The processing of parts lists, which can also be assumed by external systems, simplifies the treatment of a large number of different articles in connection with process specifications. The full recording and logging of all job and batch data produces security in relation to verification obligations. In addition to inventory administration, integrated materials management provides an integrated data basis for batch tracking.

Three decisive advantages
In the past, the production of building chemical products, such as tile cement, jointing compounds, flooring material adhesives, parquet adhesives, filling compounds, products for the base preparation and sealing materials, at the Esslingen location has not only tied up capital in the raw materials warehouse, but also resulted in high expenses for the process control in order to allow recipes to be rerun accurately at any time. In order to further expand the technological leadership that Kiesel demands for its product ranges and be able to secure this advantage, the company’s management decided to replace the existing, heterogeneous automation system landscape with a modern process control system. The decision for Plant iT was based on three fundamental features of this process control system:

• Under the modular system architecture, the control of production lines for dry goods and liquid goods is consolidated;
• Materials management is an integrated element; and
• As an open system, it uses standard hardware from various manufacturers.

Two Simatic S7 controllers with distributed ET 200M peripherals are used for the control of both production plants for dry and liquid products with 28 silos, 4 automatic scales, 2 hand-held scales for small components, 2 mixers, 2 mixing containers and 2 bottling systems. A single server provides central data management and serves as an ERP interface for booking materials in real time. A network set up just for production and the installation of operator stations at all workplaces provides employees with seamless transparency of all business processes from receipt of raw materials via production, the laboratory and packaging to dispatch.

Materials management integrated in Plant iT automatically displays the inventory movements generated by the batch system and in addition enables the execution of manual inventory movements. The permanent online view of the current status of the inventory supplies is a prerequisite for the reduction of tied-up capital – a key variable in moving towards operational excellence.

Effective production system with the smallest possible inventory stocks
The high efficiency of Plant iT can be seen in the hand weighing of small components – a well-known bottleneck in many batch processes. Plant iT also provides the operator with detailed information on upcoming jobs in several parallel screen forms, so that the small components required at a later stage can be weighed in advance in accordance with the dosing instructions at the operator station. This high degree of flexibility provides the plant operator with the freedom to plan work individually in advance and to use Plant iT so that existing experience and knowledge of operating personnel enables production to be as seamless as possible, even at the hand-dosing station. The pre-weighed small components are given a bar code label and are put into interim storage. If this specific recipe is run in the plant and the plant operator requests the already weighed quantities for dosing, the operator verifies the correct selection of the small components using a bar code scanner directly at the dosing station.

The individual components of Plant iT are controlled and gravimetrically dosed also on the production line for liquid products. The mixture containers used on this line are also administrated directly by the process control system, so that the operators always know where each container is and which product it contains.

Information on all processed materials, current consumption and amounts produced are available in real time. This creates optimal conditions for the purchase and delivery of just-in-time raw materials and thus the achievement of lowest possible inventory stocks with the lowest possible tied-up capital. In the final expansion phase, disposition of materials is handled by the materials management function of Plant iT and that begins with the receipt of the raw materials. Incoming goods are handled in future not by the ERP system, but by the process control system. The link to the ERP ensures in particular that the monetary assessment of materials stocks is updated promptly. In this way, the Plant iT process control system for Kiesel Bauchemie enables both an increase in quality by means of process stabilization and also makes the company a forerunner on the path to operational excellence in the process industry.