kanban (mostly used for repetitive manufacturing). • Based on PUSH principle. – MRP (MRP-II). • Based on both principles (push and pull). – CONWIP (Constant. CONWIP. (A pull alternative to kanban principle). Main resources: Mark Spearman, David Woodruff and Wallace Hopp. Northwestern University,. Evanson. PDF | This paper describes a new pull-based production system called CONWIP. Practical advantages of CONWIP over push and other pull systems are given.

Author: Mezinris Zologami
Country: Zimbabwe
Language: English (Spanish)
Genre: Science
Published (Last): 14 May 2013
Pages: 307
PDF File Size: 3.61 Mb
ePub File Size: 7.35 Mb
ISBN: 947-4-19702-873-5
Downloads: 60976
Price: Free* [*Free Regsitration Required]
Uploader: Sakree

CONWIP – Wikipedia

By using this site, you agree to the Terms of Use and Privacy Policy. Great feed — thank you. For example, no part is allowed to enter the system without a card authority. Of course, since the cycle of the kanban cards and the cycle of the CONWIP cards is similar, it is easy to imagine a hybrid system and it has been imagined already a few times.

The kanban can be attached to a part or be separate. Please note that this sequence is by no means fixed once it is created. Now go out and Organize your Industry! Naturally, no matter how urgent the part, if you cannot get the material there in time, there is no point in starting production.

It has some very valuable advantages, but it also comes with some disadvantages. Hence the card eventually comes back to storage again with a newly produced part. This effect is a tendency of quantity swings to increase as you go back in the value chain due to human overreaction to demand signals.


A card without a part arriving back at the beginning of the loop is an order to reproduce this part. International Journal of Production Research 28, — Both were developed by Toyota in Japan.

But since kanban are always assigned a part number, this will be difficult. If you have both, use a hybrid system.

Instead, the product type gets condip to the card on an as-needed basis. However, be aware that the risk of human decisions messing things up is there.

Benefits and Flaws of CONWIP in Comparison to Kanban

CONWIP -go-round with different parts — like roller coaster seats with people There is kanabn agreement in industry that a pull system is in almost all cases better than a push system.

Hence a CONWIP card is like a kanban card, except the part type gets assigned only on its way back when it meets the most urgent demand in the backlog.

Kanban has an additional advantage in that it automatically manages your production sequence. In their paper, Spearman et al. On the other hand, if you produce to order, a kanban will have difficulties. Your email address will not be published. In a usually highly volatile environment such as a manufacturing system, new information comes up all the time. The most famous way to establish a pull system is to use a kanban system.

This, of course, is extra work that the kanban system does not have.

This part then gets reproduced and eventually makes its way back to the finished goods of the loop. This is a kanban system in its simplest form.

However, if the parts have very different production times, then quick-and-easy parts will have a totally different workload for the production system than hard-as-nuts parts.


Assume you have blue hexagons in stock, each with a card attached. If you have high runners, use kanban, since they are easier. The backlog is a list of part types and quantities that need to be produced.

Leave a Reply Cancel reply Your email kanbqn will not be published. One of my master students analyzed this in detail and found that having one big loop or multiple smaller loops makes little difference in Kanbam for the same delivery performance. The idea of kanban is so much associated with pull production that the two terms are sometimes even used synonymously.

In the picture below, we have cards for green squares, red diamonds, and blue hexagons.

Basics of CONWIP Systems (Constant Work in Progress) |

It is doable, however. Every part must have a kanban attached with it. I hope this was insightful for you. Do you have enough space for many entries? Someone has to determine the backlog sequence i.

Basics of CONWIP Systems (Constant Work in Progress)

Material availability may also change. Sensitive to the Bullwhip Effect The bullwhip effect One effect of these human decisions is a higher tendency for the bullwhip effect.

If every product you make is unique, then you would need a unique kanban for this product.