Monday, October 26, 2009

Manual versus Information Technology Enabled Lean Manufacturing

This is Part Four of a multipart note.

The trouble is further compounded by the army of software providers (including enterprise resource planning [ERP], supply chain management [SCM], manufacturing execution systems [MES], and product lifecycle management [PLM] providers, as well as best-of-breed, bolt-on lean specialists) that have been hyping their lean capabilities, despite the fact that most of them still support mere nuggets of pseudo-just-in-time (JIT) ways of accommodating mass customization. Providing only support for kanbans, order-less repetitive scheduling, or vendor managed inventory (VMI) or supermarkets, so as to push inventory elsewhere (e.g., onto suppliers) rather than to reduce it across the entire supply chain, is a far cry from true support for lean or demand-driven manufacturing. Where most of these flow manufacturing, lean ERP, or repetitive manufacturing systems fall short is that they have simply automated the most basic of tasks within a lean environment, without addressing larger issues of how to implement lean and pull practices in environments that are not easily amenable to these.

Then again, some people question whether computer systems are even needed for achieving lean manufacturing. After all, some lean tools entail merely physical processes and best practices on the shop floor, where transactional enterprise systems have little to offer. Also, given that computers were not widely available when lean manufacturing and kanbans first emerged, many enterprises have stuck with manually-driven lean methods. For such methods, an evolutionary step forward entails the use of custom spreadsheets and reports to support lean functions such as kanban management and heijunka calculations (see Lean and World Class Manufacturing and the Information Technology Dilemma—The Loss of Corporate Consciousness). It is interesting to note, however, that even in such cases, material requirements planninng (MRP) systems still can be used to hold core master data on items and bills of material (BOM), though these records have to be tweaked with an eye toward lead time-oriented information.
Some lean purists go even further, and believe that lean manufacturing does not mesh well with information technology (IT) systems. For some, the only appropriate technology is Microsoft Excel spreadsheets. Others claim that the best scheduling method is "no schedule at all", giving the lean enterprise the utmost agility to react to any unpredictable event. On the other extreme, many people have become so accustomed to the use of enterprise systems, that they believe we can no longer return to manual procedures (see Run your Business with No Software!).

As usual, the truth might be somewhere in a middle—lean manufacturing and IT are not in opposition, and all good lean systems have both physical systems in the plant and near real time IT backbones that centralize data, especially if there is an automatic data entry and capture function. In fact, some people say that the whole point of the lean philosophy is to simplify the physical processes so that one does not need to manage overly complex data systems, though it is still necessary to manage the relevant data at the points where corrections are needed. To that end, many IT systems are designed to bring from the field only the data that management or decision-makers can do something about.

The reality is that most companies operate in a hybrid, mixed-mode environment where flow or lean and traditional batch or push manufacturing models coexist within the same facility, and where production and demand requirements can change throughout the different stages of a product's life cycle. Manufacturers can produce both high-volume goods with steady demand and low-volume goods with fluctuating demand, and their product mix may include engineer-to-order (ETO), make-to-order (MTO), and make-to-stock (MTS) items.

To successfully operate in this mixed-model environment, one has to take advantage of the strengths of each model and apply them where best suited. Thus, one should use traditional ERP systems for handling long lead-time items, one-of-a-kind production, and products with long production cycles, and for long-term budgeting and planning. On the other hand, lean manufacturing is often more easily applied to manufacturing operations with low-mix, high-volume, make-to-demand products. Moreover, one should not necessarily preclude pull-based execution processes from being implemented in to-order or highly configured operations, where it has also occasionally been done with great success.

Also, as lean spreads beyond the relatively stable manufacturing environment it was originally designed to support, companies realize that IT can play a vital role in streamlining the supply chain (see Moving Beyond Lean Manufacturing to a Lean Supply Chain). Namely, while the lean factory may use kanban pull signals to move product more efficiently through the manufacturing process and out of the door, it is missing the feedback loop from the factory to other functional departments within the organization or to the entire supply chain. That information is primarily transmitted and received via enterprise systems.
So, how can IT support lean manufacturing? For one, while complex packaged enterprise (ERP, SCM, etc.) systems may seem inconsistent with the simplicity of visual control, they actually work well together. In fact, although visual signals, such as kanbans and status indicator lights, are an effective way to trigger factory floor activities and the movement of materials, their inherent weakness is their lack of memory—visual signals cannot be recorded or tracked to determine historical performance or provide real time status for anyone that is not in direct view.

Yet, by coupling visual controls with real time collection of data from the factory floor, manufacturing enterprises should be able to capture the critical information behind the visual control signals for management oversight, planning, and accounting purposes. This information can be used for statistical analysis, to measure historical performance, and to monitor status—all of which are essential elements of the continuous improvement that lean manufacturing emphasizes. Lean aspiring manufacturers can also use enterprise systems to replace some visual controls, such as physical kanban card signals, with electronic ones, as a way to improve efficiency further and eliminate non-value adding activities.

Furthermore, these systems can play a critical role in establishing and ensuring standardized work. This is because they can serve as the central repository for critical engineering or product data management (PDM) information for standardized work, including BOMs, process routings or operations, valid product configurations, work instructions or SOPs, engineering change notices (ECN), schedule information, and costs. More robust solutions can even track as-designed, as-built, and historical actual product information, which can be analyzed to determine the impact that product changes have on efficiency and productivity.

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