Productivity analysis in a robotic cell

Abstract

In this paper, we study the productivity advantage of a variety of scenarios in a robotic cell by comparing their cycle times. The robotic cell is made up of several machines and a single gripper robot in the centre of the cell, which loads, unloads and moves the parts. Considering deterministic robot travelling, loading and unloading time elements and stochastic part process time element, this paper focuses on examining the scenarios composed of the single part type part sequencing methods and the robot moves in a cell. First, the decrease (increase) virtual robotic cell, in which its machines are virtually arranged in order of processing time regardless of their physical location, is introduced to calculate the cycle time. Second, a flow-graph based model is developed to analyse the cycle times for the scenarios when the part processing time element is stochastic. A robotic cell composed of three machines and a robot in the centre of the cell is used as a base example throughout the paper to illustrate the application of the models.