Inspection can be the begining of a lean transformation

The concepts of Lean Manufacturing are not new. Thousands of pages have been written around the benefits and implementation. Books and blogs are versing over a topic that seems to be out of date. Or not? Let’s take a look once again, as the song sings ‘from what you don’t see, believe nothing. From what you see, believe just the half’.

Old style manufacturing follows a path similar to the scheme drawn below. Products are manufactured with high tech tools and carefully studied operations, aiming to achieve the specifications consigned in the design process. Once the manufacturing process has finished, an inspection control is assesed for a percentage of the production, varying from 1 to 100%. This validation has, in the last times been done directly over the design (CAD) specs. Those products that don’t achieve the minimum specifications are rejected.

Old Manufacturing Style

Well, me like most of you have lived and worked under this manufacturing style along my professional career. Quality gurus whose names are well known came to define and implement new ‘three letter acronims’, but what was more important, to draw a feedback line in the scheme, that I have drawn in red. The objective of this dotted line, is to make the other line (cross) a reality, by elliminating non-conformities. By this mean, materials are saved, scrap reduced tools are used more effectively just in conforming products, and all this panacea that we have been listening once and again like that old LP from Carlos Gardel.

Lean Manufacturing Style

So, what’s new? Nothing, in fact nothing is new, but I believe that the last developments in computational power, and hardware technology, make Lean Manufacturing achievable by all the manufacturers who are willing to do so. For instance, by implementing a vision system in the inspection stage, can bring more benefits than expected at first. The accuracy and speed of these systems make 100% inspection a reality, without the need of stopping the production, and elliminating the famous ‘inspection bottle neck’. More and more, in some intelligent machine vision designs, no fixtures are needed for the products with different products circulating by the same conveyor. Hidden benefits are the flexibility achieved and the dissapearance of change over time for the inspection section. We are at the beggining of ‘agile manufacturing’.

If we analyze what it has been said up to this paragraph, deffective products are still being piled in the rejection bin. Right. But what about if we take some more benefits our of our newly refurbished inspection operation? TQM can be applied directly here. With the help of statistical control, parto charts and all the rest of the tool belt, the reduction of defects aiming to 0 is possible and feasible. Based on the results of the inspection, corrective-preventive actions can be taken instead of fire-fighting strategies, and with the help of Six Sigma the processes become quickly under control.

Inspection is not the only place to be for vision systems. They can also guide gripping robots to reach pieces in different orientations (did I mention the dissapearance of fixtures before?), or to assess the integrity of moulds and other tools before being used. If we think carefully, sight is the most used sense in manufacturing, from labour to machine operators, and, of course, management. Definetly, vision systems are in the prospects of every manufacturing company with a vision of future.