In a mixed model production line, different products may have different work content at different stations. Hence, some stations may need a longer or shorter time depending on the product. This requires careful planning of the assembly line. If this is not taken into account, it may cause significant idle time with all stations along the line. This is the first of a (very) long series of posts looking at Mixed Model Sequencing (i.e., the behavior of unbalanced workloads, and different ways to address these issues). Continue reading Mixed Model Sequencing – Introduction
On Adjusting Supervisor Workload
In my last post I looked at the span of control. This is very related to the workload of the supervisor. Hence in this post I would like to discuss how to adjust the supervisor workload. Usually, this is to reduce the workload, as most shop-floor supervisors are in my opinion overworked and have no time left for improvement. In some cases, however, you may have a situation where you want to give the rare underworked supervisor more work. Most of the approaches presented will work in both directions. Let’s look at some ideas: Continue reading On Adjusting Supervisor Workload
On the Span of Control
Pretty much all companies are based on a hierarchical structure. One superior manages multiple subordinates. The question is: How many subordinates should be managed by a superior? This is also called the span of control. This depends on a number of factors. Let’s have a look at efficient group sizing. Continue reading On the Span of Control
Diseconomies of Scale
The economy of scale is well known. The larger a company gets, the more efficient it becomes. However, this trend does not go on indefinitely, and eventually turns into a diseconomy of scale. In this post I will look at the diseconomies of scale, and also the very related Parkinson’s Law. Continue reading Diseconomies of Scale
Relation between Quantity and Cost in Manufacturing
As you surely know, it is more efficient to produce larger quantities. This is the economy of scale. In a recent post I talked about the Power of Six, a rule of thumb for the relation between lead time and cost. In this post I will show you a rule of thumb for the relation between quantity and cost. Credit for this rule goes to Juan Carlos Viela.
Continue reading Relation between Quantity and Cost in Manufacturing
Maintaining Weak FIFO in Parallel FIFO Lanes
Sometimes you would like to put more material in a single FIFO lane than the space you have available. In this case you would have to use a combination of two or more parallel FIFO lanes. In my last post I described how to maintain a strict FIFO sequence in parallel lanes. This post looks at an easier but less accurate method. Continue reading Maintaining Weak FIFO in Parallel FIFO Lanes
Maintaining Strong FIFO in Parallel FIFO Lanes
FIFO lanes are a common and easy way to manage material flow. However, sometimes there is not enough space to make a long FIFO lane. In this case the FIFO lane is often split into multiple sub-segments. This post looks at how to maintain strict (or strong) FIFO in such parallel FIFO lanes. Continue reading Maintaining Strong FIFO in Parallel FIFO Lanes
The Power of Six: Time and Money for Parts of Your Value Stream
In my last post I presented you Rajan Suri’s Power of Six – the relation between turnaround time and product cost. In this post I extend his work to apply it to not the entire value stream but to segments of the value stream. Enjoy! Continue reading The Power of Six: Time and Money for Parts of Your Value Stream