Evaluating Capacity
Read this article. It highlights the Toyota Production System as a process set up to understand its potential capacity, minimize its product throughput, and reduce cycle time. Analyze the Traditional Operational Availability Model for areas that could produce the greatest bottleneck.
Background
2.1. Traditional Operational Availability Model
Toyota Motor Corporation (Toyota) is known for setting the standard in manufacturing industries for producing products in the fastest and most efficient way because of the Toyota Production System (TPS). When Toyota builds a plant in Japan or abroad, TPS has been implemented to optimize the production process. It has successfully reduced manufacturing lead times, reduced work in process, and improved work environment and manufacturing operation.
On the other hands, the throughput is primary oriented toward the reduction of time required by the manufacturing process, so that the profitability can be increased. With TPS, the throughput of each step is closely connected together because of reduced inventory. A primary objective of TPS is to achieve smooth continuous flow. It is very important to identify and improve the throughput bottleneck step to improve TPS operation flow.
One main metrics of throughput evaluation is operational availability (OA). In TPS, the operational availability is defined as the probability that a system is ready to perform its mission or how well the product and process satisfies end user demands.
In traditional operational availability model, the overall throughput of a system is calculated at last step (step 4 as shown in Figure 1). However, it cannot be seen the article about the processing capacity improvement in consideration of the sequential system aspect each other.
Figure 1. Traditional Operational Availability Model
Figure 2. New Japanese Production System Model, Advanced TPS
2.2. Necessity of New Operational Availability Model
This operational availability model, as shown in Equation (1), can also be applied to evaluate each step operation status. Although the OA is a good indicator to show the throughput of the plant or even each step, it is difficult to analyze the bottleneck or to understand the reason behind the OA issues. The throughput can be affected by equipment or production issue, furthermore, short time (starvation) and full time (blockage) and other reasons. It is easy to track issues at each step but hard to judge the impact through each step to overall throughput.
The importance of quantifying elements for the manufacturing plant is to find areas for improvement. For example, if the overall OA is 92% and the OA target is 98% then the gap is 6%. If we know the 90% OA gap is due to equipment and 10% OA gap is due to production repair, the opportunity to close the OA gap for improving equipment is usually much greater than for improving production repair.
In order to accomplish TPS smooth floor, the authors have proposed a new production operational availability model to evaluate production throughput to pinpoint where to make improvements in consideration of the work delay, maintenance of facilities and the influence of sequential system aspect each other. It also helps to standardize the throughput evaluation process for global production.
2.3. Proposal of Advanced TPS for Global Production
Given this background, the authors have recognized the necessity for advancement of Japanese production management system methodologies and therefore hereby propose "Advanced TPS" as shown in Fig. 2. Advanced TPS is meant as a methodology to attain high quality assurance in global production. Advanced TPS is comprised of four different pillars: Productivity, Cost, Workability, and Quality. This proposal focuses on the pillar of productivity by implementing a system which will be able to improve and maintain efficient inventory management throughout the plant. Today we will describe the inventory management subject which is mainly in relation with the cost and productivity pillars of Advanced TPS.