As a production engineer for a multinational automotive group, I faced an intriguing challenge: doubling the production capacity of engine assembly lines for the automotive sector without disrupting the ongoing production. This classic capacity increase problem required a focused approach to optimize resources, space, and operational flows while maintaining uninterrupted production.
Welcome to our 'Lean in Action' series, where we bring you real stories from the field about the transformative power of value stream mapping (VSM). While we’ve taken care to keep identities confidential, the insights, successes, and lessons shared here are authentic accounts from lean experts and industry professionals across various sectors.
The plant produced five engine variants with components processed on dedicated lines:
- A line for machining crankshafts (single code).
- A line for machining engine blocks (three distinct codes).
- An assembly line divided into two main segments:
- Short Block Assembly: A highly automated line for assembling the engine block, crankshaft, pistons, and cylinder heads.
- Dressing Line: A more manual line for completing the engines by assembling hydraulic systems, injection, exhaust, and ignition systems.
The objective was to double production capacity without duplicating the existing lines and without significantly increasing the complexity of supply chain management.
VSM: Analysis through Value Stream Mapping
To address this challenge, we began by mapping the current production flow using Value Stream Mapping (VSM). The analysis revealed key critical issues:
- Inter-operational Buffers: Doubling the lines would have required doubling the intermediate buffers, unnecessarily increasing inventory and costs.
- Insufficient Space: Installing twin lines would have necessitated plant expansion, which was not feasible in the short term.
- Investment Costs: Duplicating the lines would have been economically unsustainable.
Lean Calculations Lead to Implementing Countermeasures
Based on the VSM analysis, takt time calculations versus cycle time, and the breakdown of operations within the cycle time, three main strategies were developed to achieve the goal:
Workplace Organization Optimization
Materials used along the lines were categorized into three groups:
- High-rotation small parts: Stored on shelves at the assembly stations and managed with a kanban signal.
- Low-cost, low-volume variable components: Prepared in kits by logistics operators in a separate area. This reduced the cycle time at each assembly station, increasing production capacity without significant structural modifications, although the takt time target was not fully met. These materials was fed in sequence.
- Bulky and high-cost components: Delivered directly to the line using just-in-sequence logic, including engine blocks, crankshafts, and pistons.
This reorganization freed up space along the lines, allowing for greater flexibility and better resource utilization.
Increasing Workstations on the Dressing Line
Through material reorganization and takt time calculations, we identified the need to add workstations to the Dressing Line:
- Line Extension: An additional segment of the conveyor chain was installed to extend the line length. During a weekend production shutdown, the chain was replaced with a longer and more flexible version, allowing for better modulation of the distance between assembly phases according to demand.
- Redistribution of Work: Workstations were rebalanced to evenly distribute workloads along the line, reducing bottlenecks and improving flow.
Twin Line for Short Block Assembly
For the highly automated Short Block Assembly line, revamping was not economically viable. Instead, a twin line was installed in an area previously occupied by a line being phased out:
- Buffer Management: To minimize inventory levels, engines assembled on the two lines were managed through a FIFO system before entering the single Dressing Line. The input in the FIFO lane define the sequence of kits that has to be prepared by logistics.
VSM & Lean: Results Achieved
These solutions successfully doubled production capacity, meeting the objectives:
- Increased Capacity Without Proportional Space Expansion: Optimizing flows allowed better utilization of existing areas.
- Improved Productivity: While the number of operators increased, it did not double, improving the output-to-resource ratio (productivity), including logistics and material handling personnel.
- Simplified Management: Flow and supply chain planning remained streamlined, avoiding unnecessary complexity.
The use of VSM as an analytical tool was instrumental in identifying potential critical issues in hypothetical scenarios and visualizing opportunities for improvement. The combination of revamping and new installations enabled a balanced approach between cost, space, and production capacity. This structured, data-driven approach demonstrated how complex problems can be resolved without compromising the quality of the production flow.
--
As you can see, the benefits of value stream mapping go far beyond the theory—it’s about real results that drive impactful change. Our lean professionals have helped countless organizations streamline operations, eliminate inefficiencies, and achieve measurable gains. Ready to see what VSM can do for you? Book a meeting with our experts today to discuss your unique challenges and get hands-on with our VSM software. Let’s start mapping your path to lean success.