Lean Manufacturing: Slim Your WasteFebruary 2008 by Ken Rizzo
Traditionally, the printing and packaging industries have looked at waste in terms of paper and substrate makeready waste, running waste, and roll waste. Consequently, printing and packaging managers typically start to look at lead time when a job enters initial production steps, such as making proofs or plates, or starting makeready on press.
Lean Manufacturing, however, looks at everything in terms of lead time of the value stream. A value stream is the time and cost of all materials and processing actions and activities that are required, starting when raw materials are delivered to the plant and continuing through the final converted product being delivered to the customer and payment received.
Throughout the value stream for folding carton operations, for example, there are two types of issues and activities that occur: value-added and non-value-added. Value-added (VA) activities are process actions that actually add value by converting the form, fit, and/or function of materials and parts into printed package products. For example, VA for a folding carton producer would include the actions of printing, cutting, folding and gluing, packaging the folding cartons, and shipment to the customer. The customer pays for and specifies VA activities. Typical VA times to produce and ship one item for a folding carton job (sheet/carton) are shown in Table 1.
Non-value-added (NVA) activities are process actions that consume resources but don’t add any value to the product, or even worse, result in product that is unacceptable to the customer. Plain and simple, NVA activities are considered waste.
Waste can be placed in eight categories from the Lean perspective, depicted by the acronym DOWNTIME (Table 2).
• Defective product—Product that is unacceptable and that customers will not pay for;
• Overproduction—Producing quicker, sooner, and more than the next process or customer needs or can handle;