In 2001, consideration and study began on implementing the Integrated Scheduled Production System, a system to produce and deliver vehicles in the order of received orders to deliver to customers high quality vehicles in the shortest time possible. With diversification of vehicle models and a growing number of options, the Integrated Scheduled Production System was the inevitable solution to reduce inventory and provide customers with "fresher vehicles" straight off of the line. In the beginning, however, many doubted the feasibility of such a system.
The most difficult bottleneck was the painting process. A speck of dust less than 1mm across vehicle cause a flaw in the paint surface, and production cannot continue to the assembly stage until such specks of dust are completely removed. Being aware of such difficulties, the challenge of maintaining the order of production, even if it means stopping the line, began in 2002.
"We cannot have succeeding production processes wait on us." This put a considerable amount of pressure on the painting staff; they needed to develop as quickly as possible a painting process that eliminated dust, and so the challenge began. In order to achieve thorough cleanliness in vehicle bodies, paints, facilities and people, approximately 5,000 causes of dust generation throughout the plant were investigated. Several hundred issues to be addressed were identified, and measures devised for each and every one of them. Then, processes and tools to control these causes as well as the training of employees who use them were put in place, finally creating a system that enabled prompt handling. Morikawa of the Hiroshima Plant says, "We stop the line and wait, and thoroughly investigate the cause. This conviction is why we were able to realize the current Integrated Scheduled Production System."
As for the results, the schedule adherence rates of the Integrated Scheduled Production System speak for themselves.
The first year adherence rate was only 49.0%, meaning that only one out of two vehicles followed the set production schedule, but four years later in 2006, the rate more than doubled to 99.1%.
The increased adherence rate made elimination of inventory, and the scheduled procurement of components expanded from in-house components to those procured from suppliers. Now, suppliers provide components in coordination with the scheduled production. Mazda also took measures to improve the logistics efficiency, such as adopting a milk-run system, where a truck goes around suppliers picking up only those components that are needed for production. Compared with 2002, the variation of production models increased from eight to nine in 2011. However, the component warehouse space has been reduced by 55%, and component inventory halved. Vehicles are flowing straight down the production line, the production leadtime has been shortened by 37%, and we are now delivering "fresher vehicles" to our customers.
Also, quality losses, operational losses, etc., of the production line have been exposed, issues were clarified for the planning of countermeasure. Due to such efforts, the 45,500 tons of CO2 emissions in 2002 was reduced to 38,900 tons in 2011, greatly reducing environmental impact.