Westlake Chemical, headquartered in Houston, TX, is a vertically integrated manufacturer and marketer of basic chemicals, vinyls, polymers, and fabricated building products. It is also the largest producer of LDPE in North America and sells this product to external customers as the final product in pellet form. .
Scheduling for the Westlake Chemical's Longview, TX, plants was manual, tedious and time-consuming and relied primarily on fragmented spreadsheets. This reduced the flexibility in handling price fluctuations, shutdowns or raw material constraints and made it difficult and time consuming to track and fix errors which propagated through the entire system. It took from four to six hours per plant to create schedules and did not allow any real time tracking of inventory level or accurate prediction of delivery for customer orders, especially change orders, or proper forecasting. This manual approach also resulted in a lack of uniformity in scheduling processes between the spreadsheet based Longview plants, which had been acquired from Eastman Chemicals and the Lake Charles, LA, facility which was more automated.
The legacy scheduling system at the Lake Charles plant had been originally provided by AspenTech, a leading supplier of software that optimizes process manufacturing — for energy, chemicals, engineering and construction, and other industries that manufacture and produce products from a chemical process. Westlake now decided to install a similar scheduling system from Aspen-Tech at Longview.
Aspen Plant Scheduler was implemented for the three Longview, TX, plants together with training for the personnel for improved user acceptance. This enabled Longview plants to now make changes to the schedule and view inventory more easily and better predict deliveries, especially for change orders. The success at long view, led Westlake management to now replicate the Longview model at Lake Charles and replace the legacy AspenTech model with the updated one. The entire deployment took only two months for both the plants as a result of the standardized capabilities and interfaces of the Aspen-Tech systems, which allowed data standardization for flows to and from the SAP.
The scheduler can assess the impact of product changeovers and downtime, as well as highlight delivery date violations, allowing customer service to negotiate new delivery dates with customers. Westlake Chemical achieved their scheduling goals of improving on-time shipments, better inventory management, more efficient product scheduling, and clearer insights into orders and forecasts thanks to
Aspen Plant Scheduler. Notably, the time to prepare a 90 day schedule was reduced from 4-6 hours to a fews minutes vastly improving customer response time.
Source: Aspen Tech