The Importance of Quality and Lean Tools in Ex Manufacturing

The world of Ex manufacturing is as important to global industry as it is satisfying to the manufacturer. The products produced are critical to the safety of personnel who work in hazardous environments. Extronics has been engineering and manufacturing Ex products for hazardous areas since 1992 and is proud to support the process industries increase their use of Smart technology, remain Safe and stay Connected.

The manufacturing process for these items begins much earlier than the shopfloor. From the design and certification stage, where the concept  is analysed for suitability and compliance, to first articles and supply chain integrity to ensure maximum quality of parts. The adage of ‘you’re only as strong as your weakest link’ is something that is at the forefront of this process.

Working within a solid process of New Product Introduction (NPI) is essential throughout this process. The NPI process ensures scrutiny at each gate review to guarantee product integrity and a successful launch. This process covers all departments and links together all the actions into a cohesive plan, with all members of the team coordinating to launch a product seamlessly and guaranteeing quality throughout, whilst maintaining the highest levels of productivity throughout a complex product range.

This article takes you through some of the key areas Extronics goes through as an Ex-manufacturer to ensure the products are built to the highest quality standards for use in hazardous environments.

The 8 Deadly Wastes

Manufacturing wastes are the biggest threats to productivity. These wastes can be unintentionally introduced, either by inadequate NPI considerations or poor execution of the inputs required for production. The 8 deadly wastes  provide a guide on how to avoid them for effective Ex manufacturing:

• Defects
• Excess Processing
• Overproduction
• Waiting
• Inventory
• Transport
• Motion
• Talent underutilisation

For this article, we will be focussing on two drivers which can directly threaten quality of the product – defects and inventory. Whilst these 8 deadly wastes must be avoided for efficient manufacture, in the Ex manufacturing industry, producing  hazardous area equipment, quality is paramount to everything that we do, there are no compromises.

Defects can be introduced into a shop floor through a lack of robust process standards, documentation, and quality control at the manufacturing level. These defects not only cause a productivity reduction within the shopfloor, with operators idle whilst issues are rectified, but if the issues are an endemic aspect of the product, there is a risk of poor-quality outputs to the customer.

Shop Floor Quality Assurance

Alongside a robust NPI process, there are other tools that we use to control and eliminate these defect risks within the process. These tools form part of the lean toolbox and are simple in their execution but powerful in their impact. In this section let us talk through a few of them, which are critical in the quality first approach.

Failure Modes and Effects Analysis

The Failure Modes and Effects Analysis (FMEA) is a proactive tool that is used at Extronics, identifying potential failures, and adjusting procedures and process to prevent them ahead of a defect becoming an issue. This is a live tool and is referred to throughout launch and during the process evaluation phase. Any issues are prioritised by a SOD (Severity, Occurrence and Detection) score, which assigns a risk factor number. This allows the team to not only identify areas of improvement but prioritise them to address larger issues rapidly and efficiently.

Total Quality Management

Total quality management (TQM) is also critical part of Extronics culture. The customer is always in mind, not only with respect to safety, but in providing maximum value. Each operator knows the importance of quality and works on the Stop, Call, Wait philosophy. If there is a problem identified, Stop what you are doing, Call for assistance if required and Wait for a complete solution before continuing. This approach minimises quality issues on the shopfloor and provides a continuous improvement and ownership culture within the process itself.

The Importance of Design

Careful consideration of production within the design process is another philosophy that is particularly important when manufacturing Ex products. This is reflected and guided by Design for Manufacture and Assembly (DfMA).

The guiding principle ensures a methodology that considers how the unit is assembled. This approach means all products are designed with an efficient build in mind.

DfMA also plays a key role in error proofing the assembly, for example when applying the POKE YOKE philosophy. POKE YOKE is a lean method that prevents faults through design, making it either immediately obvious or impossible for an error to occur. This approach might focus on a particular element of the assembly or the overall assembly to ensure it is not possible to get the assembly wrong. For example, the POKE YOKE philosophy was used in the design of the iTAG X30 guide pins moulded into the enclosure of the tag, which only allows fitment of the PCB into the tag in one orientation. Using the FMEA to implement process controls drives down the likelihood of defects, as well as 100% assurance that certification specifications are met, and the customer will receive only the highest quality products.

Incoming Part Integrity

Inventory is another potential cause of waste within production. Inventory defects are a major source of delays or wastage in production. The Cost of Poor Quality can be a hidden metric for some companies that goes unmonitored and unappreciated. Goods Inwards Inspection is a critical department within Extronics, and acts as a first barrier to this problem. Parts are inspected as per certification, declarations of conformity are required and recorded, physical metrology as well as serialisation checks are essential to ensure good onward production efficiency and high-quality products reaching the customers. This also feeds into the TQM system. If we think about how many eyes are on a component prior to shipping the finished goods; GII inspector, Kitter, Operator, Production Technician, Production Engineer, Shipping Operator – with everyone focussed on quality, micro-inspections at each stage of the production and manufacturing stage ensure the highest level of quality which is befitting of a manufacturer in the Ex-space.

Conclusion

This is just a snapshot of some of the critical components an Ex manufacturer should build into their processes in the search of operational excellence and high- quality output. The tools above and the entire suite of processes and procedures that we use at Extronics provide assurance to our customers that the Ex-products they receive will be of the highest quality. The British manufacturing industry has historically been a hallmark of quality and design and making full use of technologies and tools available globally will ensure that we continue to make innovative steps towards Industry 5.0 and beyond.

Author Bio

Pete has been Manufacturing Manager at Extronics for three and a half years. Graduating from the University of Liverpool with an Aerospace Engineering degree in 2007, he has over 15 years’ experience within the Manufacturing sector and 10 years of management experience. Through a varied range of industries ranging from optical engineering to off-highway automotive machining, he has implemented many production engineering and lean improvement projects, including efficiency improvements on the production line to managing large capital expenditure projects.