Production and Subcontracting Strategies for Manufacturers with Limited Capacity and Volatile Demand (original) (raw)

Equilibrium abandonment strategies in a cloud management system (CMS): A queueing approach

We consider a single server Markovian queueing system with geometric abandonment under multiple vaca- tion policy. Upon arrivals customers took decisions for themselves whether to enter or balk the system, based on the observation of the system-length and state of the server. In this paper, we analyze the equi- librium threshold balking strategies of customers under fully observable and almost observable cases. Using linear reward-cost structure, we find the equilibrium balking strategies in all the cases. Also, a variety of performance measures are studied under the corresponding strategies. Finally, we portray several numerical results that demonstrate the effect of the system parameters on the performance measures. Cloud computing systems with impatient users have significant potential applications in the client-server paradigm running on the user's machine such as, impatient task mapping, balancing electricity, pricing model, etc. To maintain quality of service (QoS), a serv...

Modeling and analysis of the coupled dynamics of machine degradation and repair processes using piecewise affine stochastic differential equations

This paper introduces an approach to model the coupled dynamics of recurring degradation and restoration processes that take place in real-world systems, such as manufacturing machines, in the form of non-linear (piecewise affine) differential equations. Unlike previous methods, interactions between degradation and repair dynamics that influence downtime distributions in such manufacturing systems can be explicitly considered and dependencies beyond correlations between the time between failures (TBF) and the time to repair (TTR) can be captured. The periodic solutions of the model capture the progressive evolution of long timescale failure and repair patterns. The distribution of short timescale failure–repair cycles can be captured by providing a class of random perturbations to certain model parameters. We provide sufficient conditions for the existence and stability of the resulting non-linear stochastic differential equation (n-SDE) model solutions that mimic the breakdown and repair patterns observed in many real-world manufacturing systems, namely, fairly regular (periodic) large breakdown and repair cycles, interspersed with highly right skewed distributions of short cycles. We also define the basin of attraction for the periodic orbit. The n-SDE model was parametrized using real-world data sets acquired from an automotive manufacturing assembly line segment, and the model solutions were compared with actual observations of TBF and TTR patterns, as well as the performance of the process. Our approach reduces the computation time by about 25% when compared to a discrete-event simulation model, which uses conventional TBF and TTR distributions, implemented on a commercial platform. Experimental investigations also suggest that the model can capture the correlations and non-linear coupled dynamics that exist in real-world operations among TBF and TTR, which are typically ignored in traditional approaches. Published by Elsevier Ltd.

Modeling of Production System with Nonrenewal Batch Input, Early Setup, and Extra Jobs

In this chapter, we model and solve a very general single-machine production system with early setup, bilevel threshold control, and extra job operations. The first threshold is used to control the setup starting time and the second threshold is used to control the production starting time. The system is modeled by the BMAP/G/1 queue and the manufacturing lead time is analyzed. The factorization principle is used to derive the distribution of the manufacturing lead time and the mean value. A numerical example is provided.

Evaluative Models of Discrete Part Production Lines

2009

The focus here is on discrete part production lines with asynchronous movement where each part produced is distinct. Production lines processing fluids and other continuous materials are not considered. From here on, when reference is made to production lines, discrete part production lines will be understood. In a production or flow line, all jobs are required to pass through each station in the same sequence once.