Research on Multi-Dimensional Information Service Oriented to Innovative Process Planning

The importance of process planning in manufacturing systems has been widely recognized. Process planning is a complex process with abundant information, intensive knowledge and miscellaneous experience, which leads to many challenges in its innovation. Innovation has been supported by innovative methods and information integration. However, the existing research on innovative design theory and information integration only focused on product design but rarely process planning. Therefore, it is urgent to study how to systematically use multi-dimensional information to influence process planning and realize innovative process design. An model for innovative process planning was proposed. And the general strategy of process innovation design was established. The process knowledge management and application methods were put forward, and the knowledge service system for innovative process was established. In order to support process innovation in practice, the framework of innovative process design service platform was established. Finally, a case is taken to illustrate the feasibility of the proposed method. The result shows that the proposed method can guide the designers to produce innovative process plans rapidly to solve the shortcomings of traditional process plans.

Integrated Design of Process-Tolerance for Remanufacturing Based on Failure Feature

The uncertainty failure of the used part leads the complexity selection of remanufacturing processes. The different remanufacturing process combinations among used parts of used products also make the formulation of tolerance schemes more difficult. It is hard to guarantee the optimality of process-tolerance schemes by traditional serial production modes in general, in which tolerance design is followed by process formulation. In order to generate the optimal remanufacturing scheme of process and tolerance for used products, an optimization method to integrate designs of process-tolerance (IDP-T) based on fault features was presented. In this work, the failure description set of used parts was constructed by combining the attribute characteristics and failure characteristics. Case-based reasoning (CBR) was first utilized to generate the feasible remanufacturing process plans of used parts. Then, based on the feasible process plans, the factors of cost, quality loss, closed-loop accuracy and machining ability of remanufacturing were comprehensively considered to construct the optimization model of IDP-T. The Beetle Antennae Search algorithm (BAS) was used for the optimal alternative selection. Finally, a used gearbox was taken as an example to illustrate the validity and practicality of the proposed method. The results showed that the proposed method was effective in the optimization of IDP-T for remanufacturing.

Crowdsourced Manufacturing Cyber Platform and Intelligent Cognitive Assistants for Delivery of Manufacturing as a Service: Review of Fundamental Issues and Outlook

Future cyber manufacturing is envisioned to be fulfilled in a crowdsourcing environment that will engage a large population of manufacturer crowds to collaborate with the cyber platform on a shared understanding of the tasks for delivering manufacturing as a service (MaaS). This review paper is motivated towards a symbiosis of crowdsourcing cyber platform technologies to enhance intelligent decision support to manufacturing planning for achieving MaaS operational goals. The paper reviews the fundamental issues of MaaS through crowdsourcing from a model-based systems engineering perspective that is in line with a systematic framework of platform-driven MaaS. Also discussed is the outlook of analytic and model-based approach for crowdsourced manufacturing in order to enable new cyber manufacturing capabilities that represent a significant transformation of the manufacturing sector. The vision is to facilitate transition from the current practice of focusing on automation and manufacturing informatics within individual enterprise to open manufacturing crowds throughout the cloud platform to fulfill MaaS. The cyber platform and intelligent cognitive assistants enhance MaaS fulfilment by adopting computational modeling and decision analytics to exploit the implicit design and manufacturing knowledge that is incorporated in the library of previously executed manufacturing tasks, which in turn facilitates generation of manufacturing process plans by parametric adjustment of process plans for similar tasks.

Minimizing makespan of a flexible machine under tooling contraints

Computer Number Control (CNC) milling and lathe machines are widely used in manufacturing due to their flexibility in producing parts with a wide variety of geometries. Each flexible machine has a tool magazine capable of holding a set of tools. As machining requirements for each job change, tools can be removed and different ones can be inserted so that the next job can be processed. The existing literature on the job scheduling and the tool loading can be divided into four main areas. The first area is the tool loading for a pre-specified job sequence where the objective is to determine the optimal tool loading by minimizing the number of tool switching. In addition to tool loading, the second area also focuses on sequencing the jobs too; however, the objective is the same as the first one. Rather than to minimizing the number to tool switching, the focal point of the third area has been shifted to minimizing the makespan in presence of multiple process plans. However, the main assumption is that the magazine can hold all tools needed to process all jobs and tool switching is not required. The fourth area considers the geometric and mechanical properties of the tool, assuming a tool switching may be required due to tool life. The job scheduling and the tool loading literatures do not consider multiple process plans or tool life into their problem. Therefore, the first part of this thesis provides a Dynamic Programming method to determine the optimal makespan for a pre-specified sequence of jobs, assuming tool switching may required due to multiple process plans, the capacity of the tool magazine and due to the tool life. In the second part, the assumption for fixed job sequence is relaxed and a heuristic approach is used to first sequence the jobs and then Dynamic Programming is applied to find the optimal makespan for that particular job sequence.

Minimizing makespan of a flexible machine under tooling contraints

Computer Number Control (CNC) milling and lathe machines are widely used in manufacturing due to their flexibility in producing parts with a wide variety of geometries. Each flexible machine has a tool magazine capable of holding a set of tools. As machining requirements for each job change, tools can be removed and different ones can be inserted so that the next job can be processed. The existing literature on the job scheduling and the tool loading can be divided into four main areas. The first area is the tool loading for a pre-specified job sequence where the objective is to determine the optimal tool loading by minimizing the number of tool switching. In addition to tool loading, the second area also focuses on sequencing the jobs too; however, the objective is the same as the first one. Rather than to minimizing the number to tool switching, the focal point of the third area has been shifted to minimizing the makespan in presence of multiple process plans. However, the main assumption is that the magazine can hold all tools needed to process all jobs and tool switching is not required. The fourth area considers the geometric and mechanical properties of the tool, assuming a tool switching may be required due to tool life. The job scheduling and the tool loading literatures do not consider multiple process plans or tool life into their problem. Therefore, the first part of this thesis provides a Dynamic Programming method to determine the optimal makespan for a pre-specified sequence of jobs, assuming tool switching may required due to multiple process plans, the capacity of the tool magazine and due to the tool life. In the second part, the assumption for fixed job sequence is relaxed and a heuristic approach is used to first sequence the jobs and then Dynamic Programming is applied to find the optimal makespan for that particular job sequence.

IPPS_R : a generative process planning system for rotational parts

An automated machining process planning system for rotational parts is designed, developed and implemented. The system is called IPPS_R for Intelligent Process Planning System for Rotational parts. The IPPS_R system is designed for generating process plans for manufacturing rotational parts using metal cutting operations. A generative approach is employed to determine process operations and sequences automatically. For each machining feature, based on the accuracy and surface quality requirements, a fuzzy logic approach is developed to generate machining operations. A method of ranking the machining priorities of the features according to the feature relationship matrix is developed for sequencing operations. Moreover, the heuristic search of process plans is achieved by minimizing the number of setups in a plan. Finally, the IPPS_R system with a user-friendly interface is implemented in Microsoft Visual C++ on a personal computer, utilizing Microsoft Foundation Class (MFC). Two sample parts are used to demonstrate applications of the IPPS_R system.

IPPS_R : a generative process planning system for rotational parts

An automated machining process planning system for rotational parts is designed, developed and implemented. The system is called IPPS_R for Intelligent Process Planning System for Rotational parts. The IPPS_R system is designed for generating process plans for manufacturing rotational parts using metal cutting operations. A generative approach is employed to determine process operations and sequences automatically. For each machining feature, based on the accuracy and surface quality requirements, a fuzzy logic approach is developed to generate machining operations. A method of ranking the machining priorities of the features according to the feature relationship matrix is developed for sequencing operations. Moreover, the heuristic search of process plans is achieved by minimizing the number of setups in a plan. Finally, the IPPS_R system with a user-friendly interface is implemented in Microsoft Visual C++ on a personal computer, utilizing Microsoft Foundation Class (MFC). Two sample parts are used to demonstrate applications of the IPPS_R system.

Compliance-aware engineering process plans: the case of space software engineering processes

Safety-critical systems manufacturers have the duty of care, i.e., they should take correct steps while performing acts that could foreseeably harm others. Commonly, industry standards prescribe reasonable steps in their process requirements, which regulatory bodies trust. Manufacturers perform careful documentation of compliance with each requirement to show that they act under acceptable criteria. To facilitate this task, a safety-centered planning-time framework, called ACCEPT, has been proposed. Based on compliance-by-design, ACCEPT capabilities (i.e., processes and standards modeling, and automatic compliance checking) permit to design Compliance-aware Engineering Process Plans (CaEPP), which are able to show the planning-time allocation of standard demands, i.e., if the elements set down by the standard requirements are present at given points in the engineering process plan. In this paper, we perform a case study to understand if the ACCEPT produced models could support the planning of space software engineering processes. Space software is safety and mission-critical, and it is often the result of industrial cooperation. Such cooperation is coordinated through compliance with relevant standards. In the European context, ECSS-E-ST-40C is the de-facto standard for space software production. The planning of processes in compliance with project-specific ECSS-E-ST-40C applicable requirements is mandatory during contractual agreements. Our analysis is based on qualitative criteria targeting the effort dictated by task demands required to create a CaEPP for software development with ACCEPT. Initial observations show that the effort required to model compliance and processes artifacts is significant. However, such an effort pays off in the long term since models are, to some extend, reusable and flexible. The coverage level of the models is also analyzed based on design decisions. In our opinion, such a level is adequate since it responds to the information needs required by the ECSS-E-ST-40C framework.

METHODS OF ENSURING OPTIMAL PRODUCTION PRODUCTIVITY AT ENTERPRISES

The article shows that modern production systems must be able to perform various machining operations and quickly adapt to changes in consumer demand. When planning processes, only the capabilities of production resources are taken into account, but not their quantity, availability and condition. Plans created under these conditions can easily become ineffective or invalid. Changes to the original process plans or even redevelopment then become commonplace at the production floor level. This will significantly affect the productivity of production systems and industrial enterprises.