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.
Handling a sudden increase in demand is challenging at the best of times. It gets even harder when the processes are complex and interconnected. This article takes a look at how lean tools, including value stream mapping and line balancing, allowed a manufacturer to not only meet current increased demand, but also to plan for future increases as well.
Production Capacity Increase in Complex Manufacturing Processes
A manufacturing company with complex processes, including machining, sandblasting, welding, painting and assembly, faced the challenge of increased production demand. This growth highlighted limits in production capacity: particularly in the welding department, where a 6% of gap between the required volume and capacity was identified for a specific product type.
Using value stream mapping to identify root causes and launch improvement projects
To manage this bottleneck, it was decided to temporarily outsource some welding operations. However, an analysis of future volumes showed the need for a project aimed at optimizing the production flow and structurally increasing the overall capacity of the whole process.
Two robotic work cells and three manual cells
The welding department consisted of two robotic work cells and three manual cells. These operated with an intermediate buffer before an additional inspection and pairing step, before moving the welded products to the subsequent painting operation. Through value stream mapping (VSM), it was possible to analyse the current flow, track the movement of materials, and identify waiting times between operations, measuring lead time and identifying areas of inefficiency.
The two types of components produced in the welding department were managed differently: one type, equivalent to 60% of the total volume, was produced using two robotic welding machines, while the other product was produced in manual cells.
In both cases, the production involved welding three frames using three dedicated fixtures and subsequently creating accumulation buffers before inspection and pairing, to make a kit of the three frames. These buffers resulted from the misalignment of cycle times due to variability in the work content needed to create the three different frames.
Creating a future state map with VSM for complex manufacturing processes
The initial VSM led to the development of a future state map, deployed into two steps: an initial intermediate improvement to eliminate bottlenecks and reintegrate in-house operations, followed by a subsequent re-layout project for the entire welding area, supported by new investments.
The initial optimization focused on the bottleneck represented by the manual cells, where the three separate workstations were used to weld frames with different cycle times. As mentioned, this led to buffer accumulation and the need for an additional operator to manage the buffer (handling), select, and pick frames for inspection to create the final kit.
Work sampling and spaghetti diagramming for continuous improvement
The analysis, conducted using an instant observation method (work sampling) and a spaghetti chart, led to a redefinition of the layout and the introduction of new tooling to reduce NVAs (mainly motion, transport, inventory) and level the welding cycle times across the three cells. Additionally, a "Work Combination Table" standardized the operators' tasks and balanced the workload. These measures synchronized the output times of the frames, eliminated the buffer, ensured a continuous flow of value, and freed up space for a new manual cell that covered production peaks and brought outsourced operations back in-house.
For the robotic line, a similar approach was taken: the robot's work cycle was rebalanced, with some tasks previously performed by the robot instead assigned to an operator dedicated to inspection and kit creation. This enabled a balance between the robot's activities and the operator's tasks, increasing the robot's production capacity while optimizing the use of human and mechanical resources.
Thanks to the insights gained from these workshops and the shared vision involving all departments in the future VSM, it was possible to design a new robotic welding line that integrates all operations into a single line. With flexible clamping fixtures and balanced loading and unloading activities done by operators, the process now operates without intermediate buffers. This new setup optimized space utilization, improved flow, and increased overall capacity, enabling the company to meet future market demand.
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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.