Abstract
Recently, the concept of cellular manufacturing has been introduced into the part assembly workshop as a new paradigm of improving productivity. In the assembly operations in the cellular manufacturing system, a worker plays a role of a carrier of jobs from a workstation to the next workstation or to the material supply selves to fetch assembly parts and his work is generally performed while walking in many cases. This paper presents a method for estimating walking time by individual step length based on three experiments. The experimental walking models consist of distances of 10 steps, 3 steps and 2 steps. Subjects were instructed to start walking from the standing posture with their legs put together and to stop walking with same posture. Therefore, two movements of one's legs resulted in a length of one step. Walking action is defined as two steps walking in these experiments. The experiments involving 10-step walking revealed characteristics in walking time as follows : At the beginning and end of walking, steps were not constant in length and time, but in the middle of walking, step length and time were constant. The strides of taller examinees were longer and walking took more time than shorter examinees. Individual steps also showed differences in length and time. The length of a step was proved to correlate with an examinee's height. Based on the characteristics mentioned above, it is concluded that walking time can be estimated by an equation with variables indicating the number of steps taken by the examinee and his height. Walking time for 3 steps, though low in constancy of length and time, can be estimated by an equation with variables indicating the examinee's height. Walking time for 2 steps can be estimated by an equation with variables indicating the ratio of the length of the examinees stride to their height.
