Does Levels of Automation need to be changed in an assembly system? - A case study

Production of to day is getting more and more competitive and companies have to be on top in their area in order to survive. This paper discuss if Levels of Automation need to be changed in assembly systems in order to achieve companies goals when it comes to flexibility and time minimisation. The empirical data is gathered through case studies at six different companies

Analysing changeability and time parameters due to levels of Automation in an assembly system

Products of today are becoming increasingly customized. Smaller batches in the assembly and decreasing time limits for set-ups between products are some of the resulting demands on the assembly systems, due to the increasing number of variants in the assembly flow. Consequently, assembly systems have to become more flexible and efficient. When companies adopt automated solutions, there is a need to determine the correct amount of automation. It is also necessary to identify the optimal parts of the value-flow to be automated. In automation decisions it is necessary to consider human resources, as well as mechanical technology and information flow. The paper will discuss the importance of measuring different time parameters in an assembly system. Furthermore an analysis of the ability to change level of automation in an assembly system will be discussed based on theory and a case study exampl

From Task Allocation Towards Resource Allocation when Optimising Assembly Systems

The article discusses the question; is it possible to reach route flexibility and system proactivity through resource allocation and task optimisation. In order to answer this, differences between three types of optimisation regarding task and resource allocation are discussed: Global Task and Resource optimisation, Task optimisation and local resource allocation, but with resource alternatives, Task optimisation and local resource allocation (optimisation), with prioritised resources, shown as a possible solution in this paper in order to increase the route flexibility and proactivity in the system planning. An example of the last approach will be shown using a logic language (SOP) with help of software tool called Sequence Planner (SP)

Human operator and robot resource modeling for planning purposes in assembly systems

This paper presents how robot and human resources can be modeled for planning purposes. Instead of using simplistic models such as available or unavailable resources, the method for modeling resources presented in this paper integrates parameters that are realistic and relevant for the considered assembly system. For example, a robot resource model can take into account maintenance tasks and ramp-up parameters. The framework of this modeling is based on the definition of Sequences of Operations (SOPs) and includes a formal relation between product operations and resources abilities. The main idea is to avoid the representation of long and static sequences of operations, since this typically reduces flexibility and is even intractable for large systems. To tackle this issue, relations between operations and resources are defined using only strictly necessary pre-conditions and post-conditions for each individual operation. The Sequences of Operations that permit to express the minimally restrictive behavior of an assembly system are automatically generated. Finally, the SOPs can be viewed from different angles, e.g. from a product or a resource perspective. These multiple views increase the interoperability between different engineering disciplines. Experiments have shown that, even for simple examples, obtaining the optimized assembly sequence is not an easy task. That is why a sequence planning software associated to realistic resource models, including both humans and robots, as presented in this paper, is a crucial help to increase flexibility in assembly systems that require different Levels of Automation

A classification of carrier and content of information

Mass customization is a driver for increased assembly complexity and the variety and complexity of products and parts require new and effective information and information flows to support final assembly operators. How to best present and convey information is however a difficult task. The aim of this paper is to develop a classification of carrier and content of information that can be used as a support for task allocation and design of new information systems for an assembly environment. The developed classification is mainly based on how different carriers and contents are being used in assembly and related to literature. In the design of new decision and information systems both carrier and content needs to be optimized and the concept of content and carrier needs to be contextualized in order to be useful in a task allocation and design process

Validation of the complexity index method at three manufacturing companies

In order to manage increasing numbers of product variants, tools that can reduce or manage production complexity are vital. The paper describes CompleXity Index (CXI), an index-based method and tool that assess the complexity and difficulty of work at an industrial workstation. CXI was validated at three Swedish manufacturing companies studying the correctness of the calculation, usage as a prediction tool and the view of different roles. In all three cases, CXI was seen as a useful tool to evaluate the operator-perceived complexity of a workstation

Enabling Flexible Manufacturing Systems by Using Level of Automation as Design Parameter

Handling flexibility in an ever changing manufacturing environment is one of the key challenges for a successful industry. By using tools for virtual manufacturing, industries can analyze and predict outcomes of changes before taking action to change the real manufacturing systems. This paper describes a simulation tool that can be used to study the effect of level of automation issues on the design of manufacturing systems, including their effect on the overall system performance, ergonomics, environment, and economic measures. Determining a suitable level of automation can provide a manufacturing system with the flexibility needed to respond to the unpredictable events that occur in factory systems such as machine failures, lack of quality, lack of materials, lack of resources, etc. In addition, this tool is designed to use emerging simulation standards, allowing it to provide a neutral interface for both upstream and downstream data sources

Validation of the complexity index method at three manufacturing companies

Abstract. In order to manage increasing numbers of product variants, tools that can reduce or manage production complexity are vital. The paper describes CompleXity Index (CXI), an index-based method and tool that assess the complexity and difficulty of work at an industrial workstation. CXI was validated at three Swedish manufacturing companies studying the correctness of the calculation, usage as a prediction tool and the view of different roles. In all three cases, CXI was seen as a useful tool to evaluate the operator-perceived complexity of a workstation