A work cell is a method for arranging an organization’s resources and processes in a manner that improves the quality and speed of a targeted output. This applies specifically to the personnel, equipment, and materials used in a process. Efficient organization ensures that elements of a process function well together to promote a continuous process flow. Work cells are designed to minimize extraneous motion which is a form of waste due to the input of time and energy with no beneficial output. In manufacturing, this serves to reduce the time and effort required to assemble a product, one of the main tenets of the lean approach.
Overview: What are work cells?
The concept has its origin in cellular manufacturing where each step in assembling an output is arranged into a cell that co-locate the machinery and personnel required to complete the step. The machinery is usual arranged in a u-shape to facilitate the flow of materials and so the overseer can monitor the entire manufacturing process with minimal movement. The material moves from one machine to the next in a cell until the step is complete and is then passed to the next cell in a batch manner. The proximity of workers manning the machines in a cell and their common goal facilitates teamwork and improves quality control.
3 benefits of work cells
The following benefits are achieved by organizing manufacturing floors into work cells.
1. Facilitates communication and problem solving
Communication is facilitated within a cell so that issues and concerns can be rapidly and concisely addressed. In cellular layouts, all personnel work towards a common goal and teams are more coherent.
2. Reduced waste
A cellular layout reduces staging and waiting times between departments and eliminates unnecessary transportation of parts and products compared to a traditional manufacturing layout.
3. Enhanced quality control
Quality parameters and control procedures can be tailored to the requirements of the specific part produced within a cell. This allows machinists and quality personnel assigned to the cell to quickly master the quality parameters for their cell. Quality is enhanced when cellular units are kept at a minimum operating scale.
Why are work cells important to understand?
In his book, The Toyota Way, Jeffrey Liker explains that work cells are the ultimate tool in lean manufacturing as it provides massive gains in productivity and quality while reducing inventory, floor space, and lead time. The following observations demonstrate why work cells are a key concept in the lean and six sigma approaches to process improvement.
1. Connect individual batch processes into a lean flow
In contrast to batch production which produces a large quantity of uniform products based on a single set of criteria, a lean flow in manufacturing offers precise control over product inventory with significantly reduced lead time. Using highly modular and flexible automation solutions such as robotics to fulfill as much of the manufacturing process in each work cell as possible allows easy reconfiguration and expansion of units to support multiple products as well as future growth.
2. Automation facilitates remote control
Cellular manufacturing is highly amendable to automation. Automation solutions typically have remote access capabilities built-in allowing routine changes to process programs as well as troubleshooting of errors to be made remotely. This is highly beneficial as remote work becomes the new norm.
An industry example of a work cell
Microlab is a manufacturer of high-performance components for RF and microwave distribution systems. To save time, money, and offer a larger variety of products, their batch production line consisting of spaced out, independent assembly stations was replaced with a custom engineered layout of work cells connected in a seamless, semi-automated production flow. The lean solution reduced cycle time by 90% from 20 to two minutes and reduced defects, reworks, and inventory surplus.
3 best practices when thinking about work cells
Here are some best practices for organizing work cells.
1. Group a family of parts for production
Choose a family of parts for each work cell. Constructing a value stream https://www.isixsigma.com/dictionary/value-stream/
process map identifies the necessary, value-added elements of parts family. This is useful for minimizing the variety in a particular part family and limits the requirements for changeover. If a cell is not fully utilized, the scope of production can be broadened by adding similar parts.
2. Optimize the number of machines and personnel required for each cell
Consider the requirements for material handling, workload balancing, and production scheduling for each cell. Once a plan for parts, machines and personnel has been defined, the physical layout of the cell will be easier to structure. Also consider the need for changeover and transportation of parts within the manufacturing site.
3. Employ flexible automation solutions and cross-training
The workers within a cell should be cross-trained on multiple machines in their cell to provide flexibility in scheduling and for training purposes. Automation can also provide similar benefits and can make up for gaps in worker skill levels. It is usually beneficial to automate as many processes as possible to free-up valuable human labor.
Frequently Asked Questions (FAQ) about Work Cell
1. What is takt time?
Takt time describes the average amount of time available to complete a production unit in order to meet demand and achieve on-time delivery.
2. What equipment in should go into work cells?
To more precisely match takt time between cells, automation solutions should be deployed when possible.
3. What is the optimal layout of work cells?
Work cells are typically laid out close together in a sequential order with an overall U or L-shape so that a supervisor can monitor all steps with minimal waste motion.
Looking forward
The design of effective work cells is a key lean six sigma tool for increasing the efficiency and overall performance of a manufacturing process. Focusing effort within a cell on a particular production unit kept at a minimum scale allows quick mastering of quality requirements and significantly benefits quality control. The implementation of work cells in manufacturing rapidly produces tangible benefits including reduced cycle time, a significant decrease in defects, and less waste.
