Scheduling algorithms for computer-aided line balancing in printed circuit board assembly

Abstract

Generalized Flexible Flow Line (GFFL) is a scheduling environment comprising several machine banks which the products visit in the same order but can skip some machine banks. The products are transported either in magazines or by a conveyor belt, and the change of the products demands a set-up operation of the machine. The time consumption of this operation depends on the current and the next product to be processed. This paper describes several scheduling algorithms for GFFL problem. The overall structure of these algorithms is similar, consisting of machine allocation and sequencing phases. The algorithms have been implemented and integrated into an interactive production scheduling system for electronic assembly. Sample cases are used to illustrate the operation of the system in practice.

Workflow balancing strategies in parallel machine scheduling

“…Gung and Steudel [10] determined the required set-up time reduction schemes for different levels of batch size reduction using a workload-balancing model combined with a heuristic model. Hayrinen et al [11] studied various scheduling algorithms in generalised flexible flow lines (GFFL) that had similar machine allocation and sequencing structures. Lejmi and Sabuncuoglu [12] investigated the impact of load variation on various dispatching policies in a job shop environment and found system performance was not disturbed much.…”

A low-cost printed circuit board design technique and processes using ferric chloride solution

“…It is a common compound of Iron in the +3-oxidation state. The anhydrous compound is a crystalline solid with a melting point of 307.6 [5]. The colour depends on the viewing angle: by reflected light the crystals appear dark green, but by transmitted light they appear purple-red.…”

Reconfiguring flexible machine modules of a PCB assembly line

“…Numerous approaches have been proposed for line balancing in general [4] and for PCB assembly processes [5]. For PCBs the applications differ in the number and the type of machines, in terms of the objective function (such as production cost minimization, workload balancing, process time reducing, etc.…”

“…An other possibility is to interpret the machine configuration and line balancing as a case of optimizing a simultaneous production process of a batch of identical jobs. From the point of view of line balancing the problem is of the flow line type [4,5].…”