Like all emerging methodologies, Just-in-Time manufacturing has been growing in importance since it was first conceived. However, every now and then, every single methodology, especially those around the whole supply chain idea, faces both supporters and detractors, and that is what could account for the never ending, curiously everlasting debate about the most efficient way to get materials.
Any virtual magazine or online publication will contain pages and paragraphs written by experts extolling the good characteristics of Just in Time over other systems such as Materials Requirement Planning (MRP) or Materials Resource Planning (MRP II), as if the principles behind the mere concept of Just In Time were diametrically opposed to those behind MRP and MRP II and to the necessary use of computers, systems, and technology.
The debate seems to span equally over both sides: Materials Requirement Planning, people who are fond of Just in Time attempt to explain, is solely a “push” technique. A Materials Resource Planning program seems to provide managers with less precision than it initially promises, and it also requires unnecessary information alongside other technological inputs for it to work. Reversely, those who are fond of JIT techniques seem to value the apparent computer-less “pull” techniques as kanban —the system conceived and used in the vast majority of Japan’s automobile and electronics industries—. Such scenario suggests that for those who prefer Just In Time, apparently human input or “pull” is good and, reversely, computer input or “push” is somewhat pejorative.
What seems to be especially confusing to managers who are fed up with this ongoing debate is the fact that even kanban systems are being successfully used by the same Japanese and American organizations that are known for promoting the use of advanced computer automation: Toyota or Hewlett-Packard, for instance. As a matter of fact, in some usual instances, both MRP and MRP II aim to replicate a Just In Time system, while kanban itself, due to its nature, cannot.
The debate over which system seems to yield better results needs clarity and then it subsequently needs to expire. The idealized conception people get from rather extreme Just In Time defenders and advocates —some kind of super powerful, inherently flexible and systematically inventory-less and pretty much technology-less, full of immediate-responsive suppliers— may, in fact, prevent managers from harnessing the full scope of the tools they need in order to efficiently and effectively execute their processes. Expert David Kiger has already covered the topic of Just in Time, and if something remains applicable is the fact that the idea behind Just in Time should not predict and constrain the use of both MRP and MRP II. The vast majority of advanced manufacturing and installation companies have already realized that although the myriad methodologies yield different results, it is, in fact, a hybrid system —previously tailored to include both push and pull systems like kanban or MRP II— what has proven to be effective. This mandates that managers get acquainted with the intricacies of the methodologies involved so that they can determine when a certain methodology serves no purpose and is unnecessary. Such prerequisite is compelling enough for managers and supply chain officials to develop hybrid strategies in order to effectively face their challenges: how to properly manage inventory cuts, how to quickly react to globalization, how to keep up the pace of the competition, how to deal with employees and workers, what to do with idle times, what is considered waste and what should companies do with it, etc.
It is, nonetheless, important to point out that there is indeed a huge difference between both “pull” and “push” systems, but, more importantly, one should never forget that, despite their nature, they complement each other. The basic difference between them is that “pull” systems initiates operations as a reaction to present demand, while its counterpart initiates operations beforehand: in anticipation of a plausible and future demand. Thus, many organizations, although they lean towards one specific system depending on the nature of the business, they also involve both systems at a specific time.
It is quite easy to identify the industries that have found in one system or the other the perfect opportunity to meet today’s requirements in terms of supply chain. A fast food restaurant like Burger King, for instance, runs on a pull system, while catering services operate a push system. At Burger King, the customer orders a hamburger, the employee collects one from the rack; another employee keeps an eye on the inventory while making new hamburgers; the manager orders more beef when the inventory gets low. Every time a customer purchases something at Burger King (and similar), they trigger the pull of materials required to deliver the final product. The customer, in fact, is the one who initiates the chain of demand. Reversely, in a push system, the person responsible for estimating the amount of materials for a specific order assesses how many dishes are probably going to be ordered prior to receiving an order.
* Featured Image courtesy of Unsplash at Pexels.com