Thursday, May 29, 2014

Date Codes and Shelf Life

If you ever look at labels on packaged food you will normally see the date code for when it was manufactured. It may also include the lot in which it was manufactured. Further they will include a best before date or a use or freeze before date.

The simple fact is virtually all items have a form of shelf life after which deterioration will occur. For some items that deterioration may be delayed by the manner in which it is stored. For example computer chips are stored in plastic sealed tubes to prevent exposure to the air that can cause deterioration of the materials (mostly metals). Other items may be required to be stored in specific environments to prevent deterioration.

Different companies may establish and classify shelf life of products base upon risk. Some may have non-extendible shelf lifes which if reached must not be used and must be disposed of, and
Less critical uses which may require checking to determine if they may still be used. For example you could have a 4 month shelf life, which may still be used up to 12 months if determine to be fit for use.

You want to buy from suppliers buy from suppliers that manage their inventory on a FIFO basis (First in- first out). You want that so the longest amount of remaining shelf life time available to you. As sometimes they may not have done FIFO management of their inventory, you may include requirements in your contract or specification to manage shelf life.

Once you learn what the reasonable shelf life for a specific product is, you could require that all shipments to you have a date code of no earlier than X period prior to the shipment date to make sure what you receive still has a reasonable shelf life left. The main reason for that is product that has deteriorated may no longer work in its application or use and could cause other problems. It may require you to purchase another one so you are paying twice.

One of the biggest concerns that I always had with individuals buying products from brokers rather than authorized distributors while you can check the date code, you are buying materials that someone else didn’t want. You have no idea how they may have treated or stored those materials and where and how they are stored can have an impact on the shelf life of the product.

Requiring date codes is also important in managing safety and recall of products and their cost.
Production related problems normally are identified down to the specific date(s) or lot(s) in which the problem arose. From a safety perspective if you buy products and use them to manufacture a product, you need to be able to track what materials were used in which of your products. You do that so you can identify who purchased it so you can contract them to have the item fixed or re-called. If you were able to do that you would either fix all or recall all items. If it’s a safety related problem you need to be able to do that quickly, as personal injuries and lawsuits can cost you far more.

While items have shelf lives from a life-cycle cost perspective companies need to also manage the useful life it their equipment, especially all mechanical equipment. Just like exposure to the elements can affect shelf life, it will also affect the useful life of the product. For example, you have to maintain it when you use it. Conversely, if you don’t use equipment the oils and lubricants can turn into a sludge or dry out requiring repair or replacement.

Here’s a personal tip. For those of us dinosaurs that still have and use watches, all of them have a mechanical element. They need to be used and running so the oils and lubricants don’t become a sludge or dry up. If you have an type of quartz watch sitting in a drawer needing battery replacement, you need to replace the battery so it runs. If you have mechanical watches they need to be wound so they run. If you have automatic watches you need to either wear them or have a machine that helps wind them. If you don’t, you run the risk that the mechanical parts in those watches will freeze up and that can cause either expensive cleaning and repair (if its mechanical or automatic) or could require you to replace your quartz movement.