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Lean Manufacturing

How to turn your job shop into a flow shop with material handling robots

A job shop is usually the least productive way to organize your manufacturing effort, see for instance “Why Are Job Shops Always Such a Chaotic Mess” by Christoph Roser. Yet, there are reasons job shops do not go away, and this is why you are probably reading this article.

Three products running through different stations of a job shop (left). Three products running through different stations of a flow shop (right). The representations are not equivalent and not every job shop can be turned into a flow shop.

Lets look at the reasons everyone tells you to better turn your job shop into a flow shop:

  • Flow shops are easy to measure and optimize. You can immediately see what goes in, what comes out, how long it takes and where things get stuck.
  • Flow shops are easy to automate. Each step is consistent and repetitive.

In fact, these advantages are so strong, that the advice is to essentially do whatever it takes to squeeze the processes into your job shop into a flow shop where some products simply skip certain stations.

So why would you want to stick to your job shop layout?

  • Your existing processes simply cannot be mapped to a flow shop without adding many redundant stations.
  • Flow shops take more time to setup, in particular if you have to account for all the possible products you are making.
  • Flow shops are not flexible. This becomes a problem when your products constantly change such as for contract manufacturers.
  • Flow shops do not scale well with increasing demand, but are optimized for a certain throughput.

In practice, most manufacturers already employ a hybrid model, setting up multiple flow shops within a job shop. While this provides them with an optimal trade-off in terms of efficiency, it is difficult to organize (workers need to know what to bring where) and measure and optimize overall performance.

There is a way to reap to truly reap the benefits of both approaches. Autonomous material handling robots allow you to turn your job shop into a flow shop, with the robot quite literally operating as a flexible conveyor belt that connect all of your stations equally. For example, a robot might provide a station with a shelf with new parts as well as a shelf for outgoing parts upon the press of a button. Once the process is complete, the robot will first move the end product to a new station, then remove the new incoming parts shelf.

Furthermore, the operator can obtain detailed statistics of not only what went in and what came out of a station and when, but also visualize the entire flow of an evolving product throughout the line. This is data that is historically easier to gather from a flow shop, but not necessary available.

Robotic Materials Inc. mobile manipulation solution is available for rent or purchase, contact us today!

Nikolaus Correll is the CEO of Robotic Materials Inc. and a Professor of Computer Science at the University of Colorado at Boulder. He has been designing and building large-scale distributed robotic systems from swarms of robot as small as a ping-pong ball to teams of mobile manipulating robots with fine manipulation skills. He is manufacturing robots for manufacturers in Colorado since 2016.