טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentElad Landau
SubjectJoint Stocking and Sourcing in a Multi-Echelon Environment
DepartmentDepartment of Industrial Engineering and Management
Supervisors Dr. Cohen Izack
Full Professor Shtub Avraham
Full Thesis textFull thesis text - English Version


Abstract

Traditional after-sales service maintenance models are based on the notion that sourcing of repairs to different echelons is fixed and predetermined at the beginning of the program roll out phase. We developed, for a two-echelon supply chain, a model of flexible repair sourcing when repair capability exists and is overlapping in both echelons. Such flexibility is more available today due to technology and management changes. We identified three types of repair sourcing policies which can be used, based on the relative values of repair costs and lead times: 1) central, where all repairs are sourced to a central depot; 2) local where all failures are repaired at the bases; and 3) a mixed repair policy, in which a fraction of the parts is repaired at the bases and the rest at the depot. The proposed model has led to the development of analytical results and provides managerial insights concerning joint stocking and sourcing policies. Flexible repair sourcing involves tradeoffs between cost, response time and pooling which we explore. Cases for which we could not achieve analytical results are investigated through an extensive numerical study.  In particular we focus on the effect of pooling as a function of the model parameters. The study results indicate that joint stocking and sourcing policies can potentially lead to significant cost savings compared to fixed allocation polices which are based on either cost or lead time. Using our analytical results, we suggest a heuristic solution algorithm that can be easily programmed and used in practice.