This website provides managers of small and medium sized make-to-order companies with the tools to effectively design and manage their operations towards a Lean Work Design. The objective is to protect throughput and better serve the customer at minimum cost.
An organization and its structure is not given but the result of design decision. It is the managers responsibility to consciously take these design decisions to enable everybody in the organization to take - or understand - informed decisions on physical structure, management system and job design to protect throughput and better serve the customer at minimum cost.
To take these informed decisions the right information has to be at the right time at the right place. Consequently a first group of design decisions relates to the vertical and horizontal integration of information and knowledge - When, Where, How and by Whom decisions are to be taken?
This website seeks to provide some guidance how this can be achieved. The focus hereby is on small to medium sized make-to-order companies. Therefore we seek to outline basic principles which can easily be adjusted to the unique requirements of your shop.
One of the key concepts for lean planning and and control in the context of a lean work design suitable for small to medium sized make-to-order companies is Workload Control and its card-based equivalent COBACABANA.
Based on the principles of input/output control, Workload Control provides small to medium sized make-to-order companies with many of the benefits of lean’s production planning and control techniques by leveling demand and production over time when work is not standardized and when it is not possible to synchronize flows on the shop floor. Workload Control reduces the variability of the incoming workload that results from product customization, rather than limiting variation in the product. This is in contrast to repetitive manufacturing, which typically reduces variability in the product requirements and allows the customers of small and medium-sized make-to-order companies to obtain highly customized products while ensuring a swift and even flow of work.
Workload Control is of special importance to small and medium sized make-to-order companies as it:
Allows lead times to be short, predictable and feasible;
Allows capacity to be controlled and used effectively;
Controls work-in-process and inventory, resulting in a lean shop floor; and,
Its core principles are simple in use and application (see Decision Support System and COBACABANA)
Key Definitions
Variability and Buffers
All variability in a production system is somehow absorbed by three buffers: (i) an inventory buffer, e.g. in the form of safety stocks; (ii) a capacity buffer, e.g. extra capacity to accommodate surges in demand; and (iii) a lead time buffer, which requires a flow time allowance to compensate for production variability (e.g. Galbraith, 1977; Goldratt & Cox, 1984; Hopp & Spearman, 2004).
Lean
It has further been argued in the Operations Management literature that the key to lean production is protecting throughput from variability at minimal buffer cost (e.g. Ohno, 1988; Hopp & Spearman, 2004). The emergence and subsequent popularization of lean has been one of the most significant developments in the history of operations management. Yet, many of lean’s production planning and control techniques which emphasize simplified scheduling and synchronized flow cannot be directly applied to shops that produce high-variety products. The planning environment of make to order companies is highly variable but reducing variability is often not possible, meaning that the only way to realistically reduce lead times and become lean is through more effective use of the inventory, capacity and lead time buffers.
Lean Work Design
Work is defined as “physical or mental effort or activity directed toward the production or accomplishment of something” (American Heritage College Dictionary, p. 1554). Work design is the design of the system with all of its interacting elements to accomplish work (e.g Sinha & Van de Ven, 2005). Integrating this definition with our definition of lean, lean work design can be defined as the design of an integrated socio-technical system with all of its interacting elements to accomplish work and better serve the customer at minimum buffer cost.
Workload Control
Workload Control is a production planning and control concept designed to meet the needs of make-to-order companies (e.g. Zäpfel & Missbauer, 1993; Stevenson et al., 2005; Thürer et al. 2012; Thürer et al., 2013). It provides make-to-order companies with many of the benefits of lean’s production planning and control techniques by leveling demand and production over time when work is not standardized and when it is not possible to synchronize flows on the shop floor. Moreover, it is simple in use and its principle can be implemented using a sheet of paper or any spreadsheet. It follows that Workload Control presents a key solution for production planning and control in the context of a lean work design suitable for small to medium sized make-to-order companies.