A Six Sigma process would reduce this to:
- 1 Letter lost in the post every hour
- 12 Incorrect drug prescriptions each year
This might seem an unnecessary level of accuracy in fulfillment but the customers who didn’t get what they ordered probably wouldn’t agree. Consider how much time companies spend on handling returns and customer complaints due to late, poorly packed, or wrongly delivered goods. Then consider that for every complaint there are probably 10 people who were disappointed but who couldn't be bothered to complain, and each of those customers (those representing the easiest next sell) are now far less likely to buy again.
A new method of working is required where the operator isn’t just assisted by technology, but is physically restricted from making mistakes. It may come as some surprise but the methods that follow are not the draconian dictatorship that one might image, but are infact designed to empower workers to spend their time thinking productively about their work rather then continually being forced to focus intently on every action.
Shigeo Shingo’s ‘Poka-Yoke’ (pronounced ‘poka-yoka’) techniques are an example. His philosophy relied on making an action physically impossible so that the operator had no option but the correct one. For example, given a plug with a ‘this way up’ sticker on it and with two identical pins, it is unlikely the operator will plug it in the wrong way up, but it is still possible. Add a third, redundant pin to create a 3-pin plug, and it instantly becomes impossible to get it wrong. While this example is a very physical one, the same concept can be used in any process to ensure the correct steps are followed in order.
At Six we use this technique in several places, for example, to ensure it is not possible for the wrong products to be packed, or for an order to be wrongly addressed. Many a time we’ve seen a others with a stack of paper orders for the day, going through each in turn packing. With 20-30 pieces of paper around at a time it is understandable that however vigilant, occasionally the wrong packing slip or address is likely to be used. Our solution, to only ever have one piece of paper on hand - the right piece of paper. In front of each packing station is a printer. Once the packer has confirmed the order is correct, the packing slip with integrated address label is automatically printed. (Just as a double check, the packer also scans a barcode on the packing slip, confirming it’s the right one).
While the methods used may vary, the technique is always the same - to make it very hard or impossible for an action to be done incorrectly in the first place.
Catching the Mistakes
Unfortunately when dealing with other peoples' products there is not the opportunity to design the product packaging to assist with Poke-Yoke techniques and so it is inevitable that at some point, it will be possible (although much more unlikely than by normal methods) for the wrong product to be presented, especially when dealing with awkward unmarked and unpackaged items, for example plumbing fittings.
At Six we employ yet another check, one which takes literally no time at all. Rather than weigh all our parcels at the end of the day, each is weighed just before it is sealed. At this point the actual weight is checked against a calculated weight, based on the individual weight of the items, the weight of the chosen box or padded bag and an allowance for packaging materials. If the weight falls outside of preset boundaries, then the entire process is stopped and the order is investigated to find the source of the problem.