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.
Improving On-Time Delivery and Quality in Manufacturing through Value Stream Mapping
A manufacturing company with processes comprising laser cutting, bending, machining, welding, painting, and assemblies, due to a sharp increase in demand and an expanding range of products produced, was faced with the need to improve quality performance and on-time delivery.
The main cause of quality issues for the customer were the missing parts in the final welded product that also caused, when the defect was found before shipment, the accumulation of batches waiting to be reworked and completed with the missing components pushed with urgency priority from the beginning of the material flow.
And then another cause of on-time delivery not in target was because of large batches scheduled to optimize resources and meet the production schedule on average, but smaller batches with less demand, which were sometimes also urgent remained waiting for the completion of the larger batches.
The priority of urgency of missing parts or batches in delay compromised the production scheduling and the regularity of materials and information flows.
In-depth Analysis of Problems Through Value Stream Mapping
Through a problem-solving process on the missing parts in the finished product, it was identified as a cause, that the welding process was fed by components pushed from previous stages such as machining and bending, which, however, could be synchronized to feed urgencies on other product types, not having the needed part available in time.
Thus, product types were initially identified based on the similarity of the manufacturing process, the end customer's line of use, and the demand profile.
For each product type, the as-is state value stream was mapped, highlighting accumulation points and material waiting points, process overlaps, and points where information was out of sync with the physical flow.
Lean Tools to Improve Flow and Reduce Bottlenecks
The as-is VSMs were being reviewed to ideal material and information flow to avoid missing parts and obtain 100% on-time delivery.
The welding operations were divided to product lines, one for each product type. For each welding line, the takt time was calculated based on the customer's demand profile.
In the step preceding the welding lines, a supermarket and a material picking and kitting phase was created, that simultaneously feeds the welding lines according to the levelled scheduling sent from the production planning. This makes the picking and kitting phase the the pacemaker of the whole system, to establish a cadence and organize flows according to planned work sequences. At the material picking and kitting phase a fixed lead time was given for material preparation.
The supermarket is fed by the common phases of laser cutting, machining, and bending that sequentially produce planned batches with a calculated lead time that allows the supermarket not to go on stock out.
For the common phases to the entire flow upstream of the pacemaker, the actual cycle time was compared with the required takt time to identifying bottlenecks in the flow.
Actions Taken to Address Bottlenecks
To maintain the buffer lead time to feed in sequence the supermarket at the cycle time aligned with Takt time, bottlenecks were identified in the laser cutting phase and the machining phase.
For laser cutting, it was enough to change the shift model to increase the daily availability, and making the daily target of components to be produced align with the supermarket picking takt time.
For the machining stages from an analysis of the OEE components, several causes of wastes and consequent countermeasures were identified.
A 5S workshop led to optimize the layout of the machining department by inserting fifo lanes, for each machine tool, of components to be machined according to sequences pulled from the supermarket.
A SMED workshop worked on tools, standards, and training to reduce set-up time.
A work combination table was optimized to make human-machine matching more efficient and reduce waste due to waiting. Finally, a shift model was created to enable the required takt time to be met.
Results and Key Outcomes
Insertion of the picking and kitting phase has enabled welded products with missed parts to pass from 100% to values close to 1%.
The mapping and control of flow and throughput allowed to reach 100% on-time delivery, helped also by the strong reduction of rework after welding and the strong improvement in overall efficiency achieved by the reduction of losses due to waiting, motion, and transportation.
The near elimination of missing parts, rework, urgencies, and schedule changes gave a strong boost to the environment of well-being and stress reduction among operators resulting in a strong impact on reduction of human errors.
Adopting a lean approach to visualize, identify, and resolve production constraints has brought tangible benefits and demonstrated that with the right methodology and involvement it is possible to focus resources to achieve continuous improvement.
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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.