Optimal Warranty Period when Sale-Price Increases with the Lower Specification Limit

  • Shaul P. Ladany
  • Haim Shore
Part of the Frontiers in Statistical Quality Control book series (FSQC, volume 7)


The optimal warranty period (OWP) for a product with a single critical variable (like life-time of a car battery) often becomes the manufacturer’s Lower Specification Limit (LSL). In this paper the OWP problem is addressed under the assumption that with the increase of the warranty period the cost incurred on non-conforming items grows but so is also the achievable sale-price. The OWP problem is first solved where the critical quality variable follows an exponential distribution, and then a flowchart is developed for the solution routine of the general case (any distribution). Employing Shore’s inverse normalizing transformation, a distribution-free solution is demonstrated for several numerical cases.


Control Chart Cumulative Density Function Warranty Period Statistical Quality Control Warranty Policy 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Elsayed, A., E. Reliability Engineering. Book. Addison Wesley Longman,, Inc., Reading, Massachusetts. 1996.Google Scholar
  2. 2.
    Ladany, Shaul P. Optimal set-up of a manufacturing process with unequal revenue from oversized and undersized items. In “Frontiers in Statistical Quality Control 6”, H.-JLenz and P.-Th. Wilrich (eds.). 2001. Physica-Verlag, Heidelberg, Germany. 93–101.Google Scholar
  3. 3.
    Shore, H. General control charts for variables. International Journal of Production Research, 8(8), 2000, 1875–1897.CrossRefMathSciNetGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2004

Authors and Affiliations

  • Shaul P. Ladany
    • 1
  • Haim Shore
    • 1
  1. 1.Department of Industrial Engineering, Faculty of Engineering ScienceBen-Gurion University of the NegevBeer-ShevaIsrael

Personalised recommendations