pull systems

About pull systems in processes.


Kanban is a common type of pull system in production. Kanban is the Japanese word for "signal" or "map". Pull comes from English and means "Pull". The opposite of pull is push, which translates to "Press" means. The term pull or push system is used when referring to the form of production control. Under the pull system means a principle, in which a customer order triggers a demand for the latest upstream station and thus virtually zoom pulls the necessary part.
Example of a pull system: Just imagine you're thirsty, and sit in a bar, the operator gives you constantly up a drink, even if you are at drinking. You hardly get by with drinking, because the glass is constantly threatens to overflow. Consequently, you get more than you need is. This is the push system. With the pull system, however, your glass will be filled only if you have additional needs, so they use the signal that your glass is empty.

For the production of a pull system has more advantages than the push system, as it is simpler, more efficient and more visual. In addition, the pull-based system on the retail and its needs. Ultimately produced only as much as is needed. This can be produced cost-effectively and it will avoid the generation of waste.

The Kanban principle can also be well explained using the example of the "pharmacy": Takes the pharmacist a drug's medicine cabinet, he also takes a card from the repository if the medication should be the last of its kind. This card is basically a KANBAN and thus the signal to reorder the drug. In most cases, this card is then scanned, so that the supplier knows that he needs replacement delivery. On this map of all important data are noted, which clearly identify the drug.
For the production kanban means that each downstream operation removes from an upstream only the currently required part in the required quantity and when you need them. So if material is needed (and only then) will the supplier be asked to supply new material. This notice is issued by a kanban card, which is transported in principle with each batch. There are strict rules for the production, especially the principle that should be made only when a signal is present on this. Specifically, this means that the line order kanbans can be found, which are executed. The providers see the empty or full black KANBAN containers if you have to supply goods or not.


Possible approach to implementing

First Defining the system limits for the kanban control: Kanban requires a focused and relatively constant flow of material, so the system must be checked to determine whether it is in principle suitable for KANBAN.

Second Definition of kanban loops: It is necessary to define how big the demand will be lots where the kanbans are in the system, is called when and how many will be in circulation kanbans. Computerized simulations help in complex systems.

Third Establishment of the pull principle: A perfect system passes the Fertigungsautrag the last workstation in the value chain, whereby all upstream stages will automatically receive the loop principle their respective subtasks. As long as not all power units are part of the Kanban system, it will cause problems. These increase the effort, can be avoided, but not always, since some parts are valid for long and uncertain lead times can.

4th Employee training: The basic principles and the use of kanban is to provide a training. Simulations with LEGO blocks have been established as effective tools to understand the system

5th Start: empty kanbans are passed to the upstream stage of the value chain. From there, a full container to meet demand be withdrawn. Through empty kanban the preceding stage of this is signaled to have to produce. A safety stock should not be built, because it is by the vote of the whole system is not necessary and would not comply with the kanban philosophy.

6th Stabilization phase: The material flow should be monitored, especially in the first period after the kanban device. Stocks, frequency of empty kanbans and refilling times are particularly important. The statistical process control, for example, provide optimization strategies for improved coordination of the control loops. The KANBAN system has reached a very high level when the demand lots small and few kanbans are full.


Implementation stages

Level 1
Each process is independent of the other processes. Production control is made through a plan that einlastet after the push principle orders.

Stage 2
All employees are aware of the fact that the coupling of work processes is of great importance. Basic knowledge of kanban and pull principle exists. An implementation of the pull-principle has been made.

Stage 3
The company has begun to establish interconnection points. The first steps of a production management using the pull principle and KANBAN.

Stage 4
Throughout the company, coupling points have been established. The production control system runs largely using kanban. The first steps are to combine different production lines to individual units.

Level 5
Kanban is set up and working properly. No need for security kanbans and all procurement processes run smoothly.

Synonyms
Pull System
Pull Principle
Objective
KANBAN aims to produce on the basis of perfectly matched workstations to just enough so that the needs are met exactly. The goal therefore is a material flow was minimal.
Type of method
Logistic method (material flow on)
Advantages
High employee involvement
Easy to learn and use
Reduction of control effort through loop principle
Reduction of stocks
Reduction of wastes
Improving the value chain
Disadvantages
KANBAN only useful for normalized material flows used
Operational control decisions can interfere kanban loop
Problems with fluctuating demand
Rigid system (constant polling of lots)
Quantitative results
Increasing the share of value added in the total process
Reduction of inventories
Reduction of muda species
Reduction of over-or under-production
Shortening of the information flow
Qualitative results
Extending the functions of district employees
New organizational structure and system configuration can speed up the process significantly
Increasing transparency in the work environment
Improve communication and information flow
Process phase support
-Brainstorming
no
Process phase support
Development
no
Process phase support
Work Preparation
medium
Process phase support
Production
high
Process phase support
Recycling
no
Initial efforts
high
Regular
Maintenance effort
low
Benefits (relative)
high
Benefit-cost Relations
medium
Of expense
Mean training time required
Relatively balanced mix of man-hours and material costs
Contribution to the elimination of muda
Stocks
Transport (material information)
Unnecessary movements (employees)
Overproduction
Waiting times
Aid
Gozintograph
Kanban card
Capacity Plan
Production Plan
Measurement metrics
Frequency of material per unit time views
Outstanding stocks
Average lead time material
Method linking
Workflow Analysis
By runtime analysis
Event sequence analysis
Continuous Improvement (Kaizen)
Material Flow Analysis
Production scheduling
Teamwork
Literature
Gross, John M., MacInnis, Kenneth R.: "Kanban Made Simple - Demystifying and Applying Toyota's Legendary Manufacturing Process", McGraw-Hill Professional, 2003