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Q: How do you determine the ROI on a sophisticated roller conveyor system?
Joe Keilen, product manager, Material Handling, Stiles Machinery: We calculate ROI on a roller conveyor system by evaluating several factors from improving the working environment to handling of products, and also from machine utilization and space utilization to the reduction of transport damages.
An enhanced working environment improves the employees' efficiency throughout their shift by minimizing fatigue and excessive staff turnover, which, in turn, reduces the company's training expenses.
The improved handling of products decreases employee injuries and accident along with the company's workers' compensation claims, and then results in a reduction of the company's insurance rates.
Improved machine utilization is obtained with a roller conveyor system and results in gained production capacity within the plant and/or a reduction of labor hours required at each machine.
A conveyor system also allows a company to improve its space utilization since product can be quickly and effectively moved around within a compact area, which eliminates wasted space for forklift access and vastly improves the usage of available vertical space in the plant.
In addition, the transport damages are minimized with a conveyor system to eliminate the cost of the replacement parts and delayed shipments.
Roller conveyors also enable the implementation of lean manufacturing methods and reduce the expenses associated with work in process inventory.
Peter Riehle, vice president system solutions, Michael Weinig Inc.: The ROI depends on several factors, the most important one is how the user of such a system is minimizing the manual operations necessary to handle or transfer the lumber including the complexity costs of tracking and monitoring.
Jason Varelli, key account manager RBO/Comil product manager, Biesse America: Look at the lost time created by an individual retrieving the next cart. It's very common to see an operator away from his machine looking for his next cart, and in some cases moving other carts to get to the cart they need. When adding all of your lost time, it can be substantial.
Q: When is it advisable to use carts rather than a roller conveyor system?
Keilen, Stiles Machinery: We are strong advocates of roller conveyor systems due to our numerous successes with various size shops. However, some select applications are better suited for carts.
Carts are easier to implement in older shops with numerous building additions and floor elevations — although a roller conveyor solution can work around most building constraints. In these instances, though, a cart can provide the flexibility required to handle the constraints of an older shop.
Carts are also well suited to work in conjunction with a conveyor system. For example, many plants effectively use roller conveyors when processing components and then store the completed parts in a WIP area. An employee then uses a cart to pick and organize the necessary parts from the WIP and rolls the cart of parts to the assembler.
Riehle, Michael Weinig Inc.: A roller system is suitable if you transfer between two workstations and the process is synchronized; the cycle times of the stations are almost the same.
Carts are used if:
- the workstations are not directly connected or in different locations;
- processes are not synchronized or cycle times are not the same;
- if additional buffer is needed to allow independent operation of the workstations or work cells.
Varelli, Biesse America: If you have very large parts a cart may be the best alternative. A cart can move a large part in a smaller foot-print and is more ergonomic to handle than a large part on a conveyor.
Q: Unlike other automated industries, like automotive, robots have not caught on in the woodworking industry. Why?
Keilen, Stiles Machinery: Robots have not been widely utilized up to this point in the woodworking industry compared to other automated industries due to a variety of different factors including cost, repetition and fear of technology.
The first factor is cost. The labor rate in woodworking is generally less expensive than that in the automotive industry, making the cost justification more difficult for our industry. However, as insurance premiums and labor rates continue to increase within the woodworking industry, this concern will no longer be such an issue.
The next factor is repetition. In the automotive industry, the robots are repeating the same task on the same components over and over again due to the high volumes required. In the woodworking industry, our volumes are not at the same level and, therefore, our robotic automation must be more flexible and capable of handling a wider variety of parts and tasks. Over the past few years, robotic technology has responded to the unique requirements of our industry and has implemented several tools to meet our needs. A perfect example of this is vision systems for part detection and orientation detection.
The final factor is the fear of high technology. In automotive companies, and other highly engineered industries, it is very common to have several floor engineers, programmers, etc. The woodworking industry generally doesn't have this same number of dedicated personnel simply because the sizes of our companies are smaller. For smaller shops, robotics have always come with the fear that the technology may be more than what they can handle, or perhaps the skill set required to implement and run a robotic cell (especially one that is so custom for the flexibility required that was previously mentioned) is more than they can feasibly take on. However, as the robotic control is becoming easier to use and with small shops gaining more and more familiarity with CNC controls on their processing machines, the task of taking on the robotic controls is more feasible every day.
Riehle, Michael Weinig Inc.: Robots are used in the automotive industry for the following reasons:
- 5-axis welding
- Painting
- Or precise positioning of parts or measuring operations.
The workpieces or the materials used are homogenous and consistent. In-homogeneous materials can be difficult to handle; the work holding of the robot has to fit the application. Robots are not suited for high speed applications. Robots today have to be programmed or taught, and 3-D programming can be complex and time-consuming.
Varelli, Biesse America: Robots have not caught on in the woodworking industry because they require very repetitive tasks and very competitively priced options are available. For example, you may be feeding your edgebander very small to very large parts, and this may be something a robot couldn't handle. To be a little more clear, the robot itself does nothing but move around; it's the end of arm tool that actually picks up the part. It can be difficult to manufacture an end of arm tool to meet all of your requirements. Looking at the price of robots can be deceiving. The cost of a robot by itself may look very attractive, but you typically have to double this value to cover the costs to build an end of arm tool and integrate the whole package. At this point other traditional pieces are very competitive in terms of price and capabilities.