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40 SMT Magazine • October 2014 is a finite limit on the capacity for change dic- tated by the way in which the SMT area oper- ates, in terms of planning, process preparation, and material management. This does seem like a sign of another conspiracy, one in which change is resisted; the momentum of the past is being maintained. A successful TV show always comes with a happy ending, however. It is always nice to play the hero. In our story, along comes the person who turns a progressive downward spiralling situation into a compelling need for a change, introducing a real Lean operation into SMT, not just a change in the wiring. Fundamentally, the challenge is to keep the machines running all the time. Rather than setting many lines with the same throughput capabilities, create lines with different speeds, such that for any product, a line can be cho- sen to meet the requirement for that period. As customer demand increases or decreases, be prepared to move the product to other configu- rations. The first resistance to overcome in doing this lies with planning. The assignment of work to different line configurations and the optimisa- tion of the flow are easy; there are many generic scheduling tools available to do it, even includ- ing Excel. What is more difficult, however, is to understand how to group products according to feeder layouts to reduce change-over time, which can be the most significant cause of pro- ductivity loss. A lot more data about the bill of materials is required for this optimisation. This comes from the product model as managed by the engineering team who prepare the pro- grams and necessary data for the processes that will make the product. Traditionally, there is quite a gap between these two groups of people. A decision is often made by the engineering team about how best to optimise the commonality of materials be- fore the actual work-orders, delivery times, and throughput rates are considered. This leaves the planning team with no real choices of which line configuration to use and hence, no control over the throughput. This gap needs to be elim- inated so that the wider team can consider both the optimisation of work-order throughput to meet the customer demand, and at exactly the same time, the choice of the commonality of feeders based on the set of products to be made on any line. In this way, plans can be made and revised as necessary to respond to the actual need of the customer. This is a Lean practice. The requirements for doing so are firstly to have an optimisation engine for SMT that can consider both aspects of optimisation simulta- neously, not something that ERP, traditional MES, or a spreadsheet can do. There must also be close communication, through data, of the products as they are set up on each line con- figuration. The requirement is to have a pro- cess preparation system that can manage prod- uct and process data centrally and accurately, with automated processes to assign the data in the native formats needed by each of the ma- chines in each of the lines. The automation of this leads to the products being portable, to be able to move from line to line without the need for down-time, as the programs and setup are generated, confirmed with the operation being simulated in software. The planning operation then sees multiple choices in where and when products can be made, such that the optimisa- tion engine can successfully find the best plan, for work-order sequence and for common ma- terial setup. This Lean planning can meet the most immediate of demand changes, without the compromise of operational performance. It is essential that legacy conspiracies, which exist, I am sure, in every factory today, are flushed out. It is not a matter of exposing a guilty party because there is no villain in this story. It is simply a set of circumstances that is common throughout the industry, which may have been reasonable in the past, but which now are crippling many operations. This is the compelling need for change, the compelling need to really create the Lean SMT manufactur- ing environment. It's time to stop the SMT con- spiracies! smt stOP the smt cOnsPiracY: Part 1 continues Michael Ford is senior marketing development manager with valor division of Mentor graphics Cor- poration. To read past columns, or to contact the author, click here. ThE ESSEnTiAL piOnEEr'S SurvivAL guidE

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