Images_May_2020_Digital_Edition

www.images-magazine.com MAY 2020 images 31 BUSINESS DEVELOPMENT one-piece flow. This concept broadly states that you produce something only when it is needed, and you only produce what is needed ‘just in time’ for the next process. To better understand the idea, visualise how batch and queue operations are a series of non-related and disconnected activities. Clean screens get coated, and stock gets ordered regardless of the rate of work further downstream in your operation. Work and inventory is ’pushed’ onto the downstream activity to be picked up and continued with as and when there is capacity there to do it. One-piece flow, by contrast, is a chain-reaction. Each activity sends a signal back to the prior activity and tells it when and how much to produce. In this way work is ‘pulled’ through the various value adding stages as it is required. Here are some examples, and notice how, for any of these concepts to work, they are closely tied and related to the processes upstream or downstream of them. ■ Screens are coated as they are needed, and only as many as are needed, for the following job. ■ Filmwork is produced one job ahead you’ve spent all morning shooting 25 or so screens for 10 jobs; now, let’s imagine that there happened to be an issue with that new tub of emulsion you mixed, or that the screens hadn’t been degreased properly due to an issue with the degreaser, or that your exposures were weak because your bulb needs replacing... Any number of problems can happen in production. With batch and queue, you don’t realise that the whole day’s worth of stencils are no good until the first job gets set up on the press and exhibits premature stencil failure. With one-piece flow, our issue would have surfaced almost immediately with that first job, meaning we’d lost maybe half an hour’s worth of work instead of an entire morning. ■ If it’s done right, one-piece flow is actually faster. How? Surely it’s faster to do all common processes at one time compared to constantly flitting from one process to another? This is the counter-intuitive bit! The secret is that, in one-piece flow, you are trying to get a job to go from purchase order through to completion as a near-seamless flow of value adding processes, from one area of production to the next without really stopping anywhere. In batch and queue, the time is lost because the parts of the process are constantly being set aside, and this takes time! On average, it adds around 6% of wasted time per process. In my own shop, we established our printing process as four broad areas of value adding work: of the job that is currently on press ■ Garments are ordered during the day, so that only the following day’s worth of work will arrive the following morning, and no more ■ Screens are reclaimed and cleaned as soon as a job is finished Pull system One-piece flow is what is referred to as a ‘pull’ system – inventory is pulled through the system by the process that is one position downstream. This means that there can never be over-production at any stage. Here are the main reasons why one- piece flow is being introduced into many forward-thinking organisations: ■ In a batch and queue system, the customer is kept waiting longer than necessary. That first order can’t actually be printed until all pre-press steps for all the other jobs have been completed. In today’s fast-paced, ‘need it now’ world, the shorter the time between a customer placing an order and receiving it, the more they will value your service. One-piece flow gives you the shortest possible time between order and delivery. ■ Batch and queue produces many kinds of waste – wasted time, inventory, movement, capacity, over-production, defects and bottlenecks. The ultimate aim of one-piece flow is to fill all available time with a steady rate of value-adding work in a constant stream. ■ Batch and queue allows for problems to hide in your system, and cause you big problems later on. For example, This is huge! We have 20% more capacity at no extra cost High quality Information is what makes any process move efficiently. Phantom’s drying cabinet has a clear beacon showing it is on and working, and the humidity and temperature meters have alarms to signify when screens are dry, eliminating guesswork and wasted inspection time Organisation is also key to efficient day-to-day running. These wooden tool trays are customised for what is required in various different areas. Everything is to hand, and anything missing is instantly obvious