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
Category Archives: Inventory
Production Sequences: FCFS, EDD, and Others
In my last post I looked at delivery sequences like FIFO, LIFO, etc. This second post looks at simple production sequences where you do have to deal with limited production capacity. If you cannot make everything at once, you need a sequence in which you process the parts. Continue reading Production Sequences: FCFS, EDD, and Others
Delivery Sequences: FIFO, LIFO, and Others
Sometimes, when you need a part or product from your inventory, you may have more than one item in stock. Which one do you pick? In this blog post I want to present a few strategies for choosing which item to take. The most famous one is FIFO, but there are more options available. In my next post I will present similar strategies if you need to start production before the item becomes available. Continue reading Delivery Sequences: FIFO, LIFO, and Others
Calculating the Number of POLCA Cards
In my previous posts I explained how POLCA works and discussed the pros and cons of POLCA. In this post I will explain how to calculate the number of POLCA cards. While POLCA is overall a feasible method, I do have some critical comments on the method to calculate the number of POLCA cards. Continue reading Calculating the Number of POLCA Cards
Advantages and Disadvantages of POLCA
In my previous post I described how POLCA (Paired-Cell Overlapping Loops of Cards) is supposed to work. Now let me look at the advantages and disadvantages of the method. Overall POLCA is a valid method of managing job shops. If it is the right one for you depends very much on your production system. Continue reading Advantages and Disadvantages of POLCA
What Is POLCA?
POLCA stands for Paired-Cell Overlapping Loops of Cards with Authorization and was developed by Rajan Suri around 1990. It is sometimes mentioned alongside kanban and CONWIP as a production control system. Let me explain to you how POLCA works. In my next post I look at the pros and cons of POLCA. In my last post of this mini-series, I will show you the calculation for the number of POLCA cards, including some critical comments.
The similar-sounding word Polka is also a Czech dance music and textile pattern, hence the colorful illustration of the polka dots on the left (don’t worry, more technical diagrams will follow below). Continue reading What Is POLCA?
Effect of Prioritization on Waiting Times
Prioritizing one part over others is an easy way to speed up the production of the prioritized part. However, if too many parts are prioritized, the performance of the others will suffer.
My general recommendation is to prioritize no more than 30% of your production volume. In this post I will look in more detail at this relation and verify this assumption (TL;DR: this is correct!). This post is based on a masters thesis by my student Yannic Jäger. Continue reading Effect of Prioritization on Waiting Times
Twelve Ways to Create Space around Your Assembly – Part 2
The spaces around your assembly locations are most precious. In my previous post I explained how to relocate or reduce the overall material quantity. In this post I focus on how to better use the area facing the worker. Ideally, all material should be within easy reach of the worker. Continue reading Twelve Ways to Create Space around Your Assembly – Part 2