What is a Pull System?
A pull system is a Lean technique for reducing the waste of any production process. Applying a pull system allows you to start new work only when there is a customer demand for it. This gives you the opportunity to reduce overhead and optimize storage costs.
Why Is Pull Better Than Push?
Pull systems are part of the Lean manufacturing principles, born in the late 1940’s. A lean pull system has the purpose of creating a workflow where work is pulled only if there is a demand for it.
Essentially, the purpose of implementing a pull system is to build products based on actual demand and not on forecasts. By doing so, your company can focus on eliminating waste activities in the production process. As a result, you’ll be able to optimize your resources and reduce the possibility of overstocking.
Furthermore, applying a pull system will allow you to deliver work just in time.
“Just-in-time” is a production model where deliverables are produced in order to meet actual demands and avoid overstocking and push strategies.
When applying a push strategy, a company’s production is based on anticipated demand, which can fail to correspond with the actual demand. Such an imbalance can create unexpected financial gaps.
In knowledge work, the “just-in-time” concept can be applied in the same way as in manufacturing – a work item has to be in progress only if there is a demand for it.
This is the opposite of “Just in Case”, where companies somehow try to ensure themselves by overproducing in case of higher demands somewhere in the future.
Apple is one of the brightest examples how a pull system can be successful. Have you ever seen these long waiting queues in front of the Apple stores during the latest release of iPhone?
Apple always creates a buzz around their new products and consumers are always ready to buy. They want to pull the product from the stores.
Apple doesn’t overstock their shops or retail partners. They wait to see if there is a demand for more and if it increases, they produce more. This way, the company optimizes its resources and achieves high-cost efficiency.
How To Manage a Pull System?
Nowadays, the pull system concept is widely spread across various industries. Professionals use it not only in manufacturing but also in software development, customer support and more.
In the context of workflow management, a pull system allows workers to pull their next task if they have the capacity to start working on it. This may help you prioritize tasks better and prevent teams from overloading. By doing so, your team can stay focused on executing the most important work just in time.
To achieve higher levels of productivity and workflow efficiency by using a pull system, you need to:
Apply pull signals
First of all, you need to establish pull signals. The best way to do so is by building a visual workflow, where all valuable information can be recorded and tracked. This first step will help you acquire a full overview of your work process and catch all important signals.
Control the system
After building a visual pull system, you need to know how to control it. One of the most common ways to manage your pull system effectively is by limiting work in progress (WIP). This is one of the core practices of the Kanban method, which is a widespread pull system.
For example, on a Kanban board, your workflow is divided into different stages such as Ready to start, In progress, Waiting for review, Ready for delivery and etc. By limiting the work that can be in progress at each stage, you will be able to create a smooth workflow and identify problematic parts in it.
This may misguide you to the illusion that by creating a single-tasking model, your team will not use its full capacity.
Contrary to the common belief that we should multitask in order to finish more work, limiting your WIP will actually let your team members focus on single tasks until their completion.
While being focused, your team will be able to achieve excellence through flow and deliver work much faster.
However, limiting work in progress will not be enough to build a sustainable pull system. You will also need to limit the time a single item can spend in your system.
This limit may vary depending on the size of a task and it will serve as a requirement. If you forget to do so, some tasks may spend a great amount of time in progress and reduce the flow efficiency.
Advantages of Using a Pull System
Unlike push systems, which force team members to work on multiple tasks, a pull system lets team members focus on a single work item at a time. This approach allows a work unit to:
- Quickly adapt to changes that may occur in the work process
- Scale the optimal capacity of your team
- Deliver work items much faster
- Reduce waste of resources
- Increase productivity
- Improve flow efficiency
Actually, by using lean pull principles, you can be much more predictable when planning your future work. How is this possible?
Pull systems allow you to collect historical data about your workflow and the average cycle time of tasks.
Using this data in combination with different forecasting techniques such as the Monte Carlo simulation will give you a probable forecast about how much work can be processed in a predefined period of time.