Case Study
Reducing Press Changeover Time Using SMED Workshops and a Daily Management System
Summary
Our customer, a global industry leader generating a revenue exceeding £2 billion, specializes in delivering refractory products, systems, and solutions to steel producers and various high-temperature industries. In an effort to minimize equipment downtime, their Johannesburg subsidiary sought assistance in deploying Lean tools. Rather than relying on resources from their main operations in Europe, the global group opted to engage a local organization. The Plant Manager in Johannesburg was particularly impressed by Lean Institute Africa’s proposed approach. It not only addressed the immediate performance issues but also emphasized the development of internal capacity for ongoing improvement.
Understanding the problem
The primary focus of attention was on the Brick Plant, responsible for manufacturing refractory bricks in various shapes and designs for furnaces and smelters. In the year 2022, the Overall Equipment Effectiveness (OEE) performance of the plant averaged 55%, falling below the targeted 58%. An analysis highlighted that changeovers were the major contributor to lost time on their presses, accounting for approximately 20%. Responding to this, the management team decided to raise the OEE target to 60% and sought our expertise to conduct SMED (Single-Minute Exchange of Die) workshops. The goal was to streamline and reduce changeover times on their presses.
Upon initial assessment of press changeover times, a critical issue surfaced: poor data collection for changeovers. The collected data exhibited significant gaps, with an average data completion rate of only 46%. Addressing this challenge became the first priority in the quest for improvement.
Proactive utilization of data for managing changeovers was lacking, with production log sheets serving as the primary source for downtime information. Recognizing the critical role of data analysis in the project, a target of 85% data completion was established.
The average durations of changeovers and the capability to execute them within the allocated times significantly deviated from the anticipated performance levels. The initial baseline data for the two types of changeovers stood as follows:
Die changeover time reduced from 5 hours and 52 minutes in August 2023, to 3 hours and 13 minutes by November 2023, marking an impressive 45% reduction in changeover time.
How the changes were implemented
The engagement’s design was crafted utilizing the Double-Loop PDCA (Plan – Do – Check – Act) framework, seamlessly integrating Rapid Improvement Events (Kaizen Events) with routine team improvements through a Daily Management System. The Rapid Improvement Events, spanning five working days, were dedicated to refining the SMED process and thus were termed SMED Workshops.
These workshops convened a cross-functional team comprising essential stakeholders in press changeovers: Press Operators, Die Setters, Die-Setting Coordinator, and Supervisors. Their collective responsibility was to pinpoint key improvements and major updates for the press changeover standard. The standards derived from the workshop became pivotal documents for guiding and tracking daily operations. Any performance gaps identified in the daily work were documented and served as triggers for subsequent workshops.
Measurable outcomes and impact
Originally, the intention was to conduct three workshops; however, the set targets were achieved by the conclusion of the second workshop. The performance graph for the two Double-Loop cycles is illustrated below:
Plate changeover time reduced from 3 hours and 24 minutes in September 2023, to 1 hour and 54 minutes by November 2023, reflecting a substantial 44% reduction in changeover time.
Die changeover time reduced from 5 hours and 52 minutes in August 2023, to 3 hours and 13 minutes by November 2023, marking an impressive 45% reduction in changeover time.
Data completion rate, which stood at an average of 55% in July, demonstrated significant improvement, reaching an average of 92% by November 2023.
