Category Archives: Inventory

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

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