DE / EN
Dr. Johannes Diefenbach (né Schnitzler)

Dr. Johannes Diefenbach (né Schnitzler)

Research Assistant at the Chair of Production Management
University of Mannheim
Schloss Schneckenhof Ost SO 213
68161 Mannheim
Phone: +49 621 181–1482
Fax: +49 621 181–1579
E-mail: diefenbach bwl.uni-mannheim.de

Dissertation Project

Design and Control of Stochastic Manufacturing Systems

Date of Defense

15 July 2022

Research Interest

My research focuses on the design and control of stochastic manufacturing systems. Problems include the optimal design of an assembly line with generally distributed task times or the start of production decision in the ramp-up of semiconductor manufacturing. 

Our research focuses on the design and control of stochastic manufacturing systems. Flow lines are common in many industries producing in large quantities. We analyze the assembly line balancing problem with stochastic task times. We consider the optimization problem of minimizing the number of stations with a constraint on the probability of finishing a work piece within the given cycle time. Technical precedence relations have to be fulfilled and each task has to be assigned to exactly one station.

In addition to this design problem, we analyze the optimal start of production in a ramp-up process which faces stochastic yield. Yield problems occur when some of the produced products do not meet the specifications and can therefore not be used to fulfill demand. The yield distribution of a production process could change over time, depending on the past production volume.