Thesis Details

Thesis Title: An economic comparison of various operating strategies in the spinning room
Thesis Author: Nevil Gott
Abstract: In recent years, textile mills have been faced with the problems of high labor turnover and absenteeism. This has been a particularly serious problem among spinning frame doffers, and various remedies have been tried to solve the problem. One solution is the redeployment of doffers, and, to a lesser extent, spinners, in different strategies which would utilize the existing labor in the best way. This thesis covers the development of a dynamic simulation model of the spinner and doffer jobs. It will enable comparisons to be made between various operating strategies with emphasis on the doffing, piecing, and creeling work. Two models were developedl one model for a conventional spinning room in which the doffers and spinners work independently; the other model for a combination of the doffer and spinner work into a single job. The conventional spinning room model is a combination of two basic routinesl a doffer routine and a spinner routine. In operation the doffer routine simulates the doffing of frames during a selected increment of time. For convenience this time period was selected as the spinner cycle time. At the end of each doffing time increment, the spinner routine simulates the piecing and creeling work at each side in the assignment for one cyole. The simulation alternates between the two routines until the desired simulation time is reached. The model was validated against data from a Member Mill, and several strategies were simulated and compared. A doffing labor cost was determined for the main strategies used. One of the strategies simulated was the combination of doffer and spinner work into one job. This entailed the development of a second model to simulate the combined work. As part of this model, a method of generating piecing and creeling occurrences per side was developed in which the frequency of occurrences was related to the time elapsed since the last service. The computer programs of the two models are available for use or adaptation by mills.