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Cost analysis of robot families

Written by Martin Björkman

Paper category

Master Thesis


Business Administration>Finance




Master Thesis: Robot family and platform analysis As stated in the theoretical review: "A product family is a collection of similar products based on the characteristics/functions of a common platform". The robots in the IRB 6640 series all operate in the same way. They use the same technology and share some components. For example, all robots have the same gear in joint one, the same gear in joint two, and the gear in joint three. same. In addition, individual robots with the same range share basically the same hardware. Obviously, the IRB 6640 series supports the basic theoretical ideas behind the product line thinking. If you look back at the definition of the product family mentioned above, it needs to be built on a common platform. To some extent, the 6640 series is built on platform thinking, because individuals share some components, but the type of platform used is unclear. 4.1.1 Modular platform When redesigning the robot family, a common method is to change the range and payload of the individual robot to see how performance requirements (such as rated torque) affect the choice of motors and gears in the joints. If the range changes, a new arm is also needed. With this in mind, a modular platform would be appropriate, as new robots are created by configuring existing components. It is described in the theoretical commentary that the design method of the configuration product series should be aimed at developing a modular product platform, from which product series members are derived by adding, replacing and deleting one or more modules. This actually supports the choice of modular platforms. Specifically, the modular platform should be composed of different gears, motors, lower arms, upper arms, etc., and restrict how the components can be assembled together. 4.1.2 Analog cost model When the configuration/interface of the component is changed, the cost of the robot will be affected. The more the interface changes, the greater the cost impact. For example, if the gears of the joints are changed, the gears and robot interface may need to be changed. The change in cost is related to the degree to which the interface needs to be changed. The supplier's investment cost, test time, changes to assembly manuals, etc. usually become larger as the interface changes. Therefore, it is appropriate to choose a similar model to estimate these cost changes, because the difference between existing and new components/interfaces determines the difference in cost. In addition, the robot series design is completed in the early design stage, where the uncertainty is high and the lack of detailed information is a fact. Therefore, it is important to keep similar models simple and focus on large costs. 4.1.3 Behind the analogy model used by the internal product configuration system is the knowledge and information needed to understand how products, components, and processes are similar and different. In order to manage this, ABB needs to use its internal product configuration system to facilitate this information. The internal product configuration system should not only contain the necessary information required by similar models, but also the specifications of the production/logistics process. Considering the theoretical framework of product series design and development, the internal configuration system should focus on supporting the connection between the physical, process, and logistics domains, as shown in Figure 22. Since the configuration system is intended for internal use, it is convenient for participating teams to include information from the assembly and logistics process in the design process, and it is not necessary to include external contacts with customers. However, when the system is implemented and operational, ABB may add customer concerns to the system by connecting these domains. But it is not necessary at this stage, because the research focuses on the cost perspective and has nothing to do with the market perspective. Figure 23 describes the regional functions of the internal configuration system. It is very important for the different teams involved in the design process to jointly develop and formulate the specification process, so that these processes can remain stable over time and play a good role in practice. The standard process type to be developed is "Modify to order", which is suitable for robot family design and supports module-based products. Since ABB adopts an assembly-to-order (ATO) production strategy, they have appropriate preconditions to increase their future level of customization. By expanding the configuration system of the customer domain and developing a standardized process for order processing, customers can obtain robots assembled in accordance with their specific orders to better meet their requirements. On the other hand, the robot design process is very complex and is based on many manual design steps. Therefore, this is a configuration system in which customers can "assemble" their own robots, which is a far cry from today's design methods. To make this possible, the design process must be automated, which will speed up the personalized design process for custom orders. Another solution is to pre-determine each possible design configuration, and pre-calculate the performance and cost of each possible configuration. 4.2 Life cycle cost analysis of robots 4.2.1 IRB 6640 series Judging from the characteristics of IRB 6640's life cycle length and total life cycle cost, it is obvious that robots are "medium-sized", as shown in Table 5. Read Less