Feature based sequence planning and assembly system design using Petri net | |
| Author | Ullah, Hamid |
| Call Number | AIT Diss. no.ISE-07-05 |
| Subject(s) | Petri nets Computer integrated manufacturing systems |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering in Design and Manufacturing Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. ISE-07-05 |
| Abstract | Assembly feature's definition is provided after carrying an extensive literature review of the existing assembly feature definitions. The new assembly feature's definition uses the concept of assembly intents. Assembly intents include assembly relation, assembly operation, and assembly degree of freedom which are all the necessary information required within assembly. This definition of assembly feature is used in the development of a feature conversion mathematical model. The conceptual model is developed to show how design features (in design domain) are converted into assembly features (in assembly domain). The definition of assembly feature also provides a basis for the new broad classification of assembly features based on assembly-specific information it provides. A new classification of assembly features is made based on necessary assembly-specific information. Significance of the assembly features classification is demonstrated and important information and advantages are identified which the assembly features offer to facilitate the process of assembly sequence planning. For example, assembly features provide sophisticated knowledge such as assembly order, pattern of identical components, and multiple assembly features and describe how the components can be assembled together using this knowledge of assembly features. This knowledge represented by assembly features facilitates assembly sequence planning, resulting in a significant lower number of feasible sequences that have to be checked for the assembly sequence optimization. Due to the reduction in the number of assembly sequences, the AND/OR graph not only shrinks considerably but also becomes very simple. This reduces the search space for the optimum (or near optimum) assembly sequence. Weights are assigned to the arcs of the AND/OR graph to take into account mating of components through a number of features connecting together simultaneously. For the design and performance evaluation of an assembly system, a new generic Petri net model is developed. It is also used to determine the near optimal assembly sequence using a multi-criteria approach. The Petri net model is first of its kind, having many important advantages. For example, it is provided with a transition to provide feedback for replenishment of new components into the input places as soon as the final assembly is produced at the output place of the Petri net. It takes into account assembly line balancing in the design and performance analysis of the assembly system. It pushes more inventory to the initial assembly phase. The Petri net is initially developed without dual kanban. It is then extended for inclusion of dual kanban. The proposed research is demonstrated with the help of real-life examples. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. ISE-07-05 |
| Type | Dissertation |
| School | School of Engineering and Technology (SET) |
| Department | Department of Industrial Systems Engineering (DISE) |
| Academic Program/FoS | Industrial Systems Engineering (ISE) |
| Chairperson(s) | Bohez, Erik L. J.; |
| Examination Committee(s) | Afzulpurkar, Nitin V. ;Dailey, Matthew N. ;Janssens, Gerrit Karel Eugeen ; |
| Scholarship Donor(s) | NWFP University of Engineering and Technology, Peshawar, Pakistan; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2007 |