IIM Indore seeks to be a contextually-relevant business school with world-class academic standards that develops socially-conscious managers, leaders and entrepreneurs. IIM Indore is committed to: Excellence in management education, research, and training, Use of contemporary participant-centric pedagogies and teaching methods, A presence in emerging segments of management education.

IIM Indore

Operation Management and Quantitative Techniques

The purpose of this research is to demonstrate an application of TOC's thinking process (TP) in a blood bank environment. We take an example of a real-life blood bank which is struggling with the problems of high shortage and wastage of blood products, large inventory levels, poor and erratic blood collection, limited product variety, high error rate, high turnover of technicians, high operating expenses and low revenue levels. We show using the TOC approach how these seemingly unrelated problems faced by the bank are in fact highly inter-related and how they all originate from a single root-cause. A current reality tree (CRT) is used to identify the root cause responsible for all the major blood bank problems. A conflict resolution diagram (CRD) is constructed to identify the core-conflict(s) responsible for the blood bank's poor performance. A simple yet powerful solution is generated for the given bank by breaking the core-conflict resulting from a paradigm constraint in blood banking. A future reality tree (FRT) is then constructed to show how the TOC approach will help the blood bank in lowering its shortage and wastage levels in spite of collecting lesser number of units in blood donation camps. The bank will be able to significantly cut down its inventories and can issue fresher units to the patients. Blood bank's revenue levels will increase while its operating expense will decrease due to the TOC approach. The error rate as well as the turnover of technicians in the blood bank laboratory will also reduce considerably. A simulation model shows that the proposed TOC solution will reduce the annual shortage of red blood cells by 66% and platelets by 82% at the bank. Similarly, the wastage of red blood cells will decrease by 93%, plasma by 99% and platelets by 98%. The average inventory level of the red blood cells will drop by 41%, plasma by 95% and platelets by 10%. The major contribution of this research is to show that TP tools can be extremely powerful in constructing win-win solutions for complex systems like blood banks by addressing their major problems in an integrated fashion. The TOC approach reveals how one widely-held belief in the blood banking world is the main reason behind the blood banks' poor state of affairs. The solutions presented in this research should be readily applicable to other blood banks which are struggling to improve their operational and financial performance.

World University root node

International Journal of Production Economics

Revolutionizing blood bank inventory management using the TOC thinking process: An Indian case study

The progressive Type-II hybrid censoring scheme introduced by Kundu and Joarder (Computational Statistics and Data Analysis, 2509-2528, 2006), has received some attention in the last few years. One major drawback of this censoring scheme is that very few observations (even no observation at all) may be observed at the end of the experiment. To overcome this problem, Cho, Sun and Lee (Statistical Methodology, 23, 18-34, 2015) recently introduced generalized progressive censoring which ensures to get a pre specified number of failures. In this paper we analyze generalized progressive censored data in presence of competing risks. For brevity we have considered only two competing causes of failures, and it is assumed that the lifetime of the competing causes follow one parameter exponential distributions with different scale parameters. We obtain the maximum likelihood estimators of the unknown parameters and also provide their exact distributions. Based on the exact distributions of the maximum likelihood estimators exact confidence intervals can be obtained. Asymptotic and bootstrap confidence intervals are also provided for comparison purposes. We further consider the Bayesian analysis of the unknown parameters under a very flexible Beta-Gamma prior. We provide the Bayes estimates and the associated credible intervals of the unknown parameters based on the above priors. We present extensive simulation results to see the effectiveness of the proposed method and finally one real data set is analyzed for illustrative purpose.&nbsp;

Fulltext

Metrika

<a href="https://link.springer.com/content/pdf/10.1007/s00184-017-0611-6.pdf">On generalized progressive hybrid censoring in presence of competing risks</a>

The goal of this research is to jointly study physician prescription decisions and patient drug request behaviors. We have adopted a binary logit model and a multinomial logit (MNL) model to study patient drug request data with excessive zero requests and a MNL model to capture physician prescription decisions. These models are further joined by a flexible nonparametric multivariate distribution for their random effects. We also adopt an analytically consistent expression for interaction effects in our non-linear and joint modeling framework. We apply our model to a unique physician panel data set from the Erectile Dysfunction category. Our key empirical findings include the following: (1) the triggering of drug requests by DTCA is complex with category level DTCA reducing patients' probabilities of making drug requests and drug specific DTCA driving drug requests for the advertised drug; (2) patient characteristics may play a role in both the impact of DTCA on drug requests and the impact of patient requests on physician prescription decisions; (3) patient drug requests have a positive impact on physician prescription decisions and patients can be consistent with physicians in choosing a drug based on their diagnosis levels and some unobserved factors; (4) there are significant correlations among physician-level random effects that drive both patient drug requests and physician prescription decisions, which validates the joint modeling approach.

Journal of Royal Statistical Society: Series A

Ask Your Doctor If This Product Is Right for You: A Bayesian Joint Model for Patient Drug Requests and Physician Prescriptions

We develop a dynamic zero-inflated model to analyse the number of hospital admissions within an aging population, which allows for the considerable number of zero hospital admissions at the individual level and occurrence dependence. In addition, certain health conditions may lead to groups of individuals having similar hospital admission rates. We analyse the US Health and Retirement Survey, which includes selfassessed health (SAH), which can be predictive of hospital admissions. Our modelling framework embeds a dynamic hierarchical matrix stick-breaking process to flexibly characterize this dynamic group structure allowing individuals to belong to different SAH groups at different points in time.

Sheffield economic research paper series

A Semiparametric Bayesian Approach to a New Dynamic Zero-Inflated Model

Most self-help groups (SHGs) in India are social enterprises owned and operated by poor women. They have helped to create women entrepreneurs in the rural areas of the country. Though these SHGs are producing a large number of products with superior quality, they fail to sustain in the market. To address this problem of sustainability and marketability of SHG in Kerala, India, an attempt has been made to develop a sustainable marketing model of SHG using analytical hierarchical process (AHP). The objective of the study is to enable a SHG find out the most appropriate mode of finance, branding and positioning strategy, promotional strategy and appropriate production aspects of such products. Based on the feedback obtained on the critical areas and the practice of successful self-help groups in Kerala, this paper develops a marketing model for SHGs in Kerala.

International Journal of Services and Operations Management

Development of a sustainable strategic marketing model for self-help groups - an analytical hierarchical approach

The operational efficiency of the food and beverages industry is determined by identifying the technical and scale efficiencies by applying data envelopment analysis (DEA) models. A set of 46 companies with average data collected for the year 2005-2006 to 2009-2010 is used for the study. The analysis begins with a benchmark study, followed by identification of peers and their followers. Nine firms emerge as peers. The slacks of the inefficient firms are identified. Regression analysis is used to estimate the causal relationship between operational efficiency and the other chosen variables. Analyses of peer firms are conducted to identify the influencing variables of the peer firms. The first stage DEA analysis reveals that the inefficiencies such as scale and technical inefficiencies exist in the Indian food and beverages industry and a majority of inefficient firms are operating in the increasing returns to scale region. The second stage analysis using the OLS regression to identify the determinants of these inefficiencies reveals that current ratio and financial assets to total assets are contributing significantly to the inefficiencies.

Operational efficiency and its determinants of Indian food and beverages industries: a DEA approach

Kundu and Gupta [22] provided the analysis of Type-I hybrid censored competing risks data, when the lifetime distribution of the competing causes of failures follow exponential distribution. In this paper we consider the analysis of Type-II hybrid censored competing risks data. It is assumed that latent lifetime distributions of the competing causes of failures follow independent exponential distributions with different scale parameters. It is observed that the maximum likelihood estimators of the unknown parameters do not always exist. We propose the modified estimators of the scale parameters, which coincide with the corresponding maximum likelihood estimators when they exist and asymptotically they are equivalent. We obtain the exact distribution of the proposed estimators. Using the exact distributions of the proposed estimators, associated confidence intervals are obtained. The asymptotic and bootstrap confidence intervals of the unknown parameters are also provided. Further, Bayesian inference of some unknown parametric functions under a very flexible Beta-Gamma prior is considered. Bayes estimators and associated credible intervals of the unknown parameters are obtained using Monte Carlo method. Extensive Monte Carlo simulations are performed to see the effectiveness of the proposed estimators and one real data set has been analyzed for the illustrative purposes. It is observed that the proposed model and the method work quite well for this data set.62F10, 62F03, 62H12

arXiv

Analysis of type-II hybrid censored competing risks data

The progressive Type-II hybrid censoring scheme introduced by Kundu and Joarder (Computational Statistics and Data Analysis, 2509-2528, 2006), has received some at- tention in the last few years. One major drawback of this censoring scheme is that very few observations (even no observation at all) may be observed at the end of the experiment. To overcome this problem, Cho, Sun and Lee (Statistical Methodology, 23, 18-34, 2015) recently introduced generalized progressive censoring which ensures to get a pre specified number of failures. In this paper we analyze generalized progressive censored data in presence of competing risks. For brevity we have considered only two competing causes of failures and it is assumed that the lifetime of the competing causes follow one parameter exponential distributions with different scale parameters. We ob- tain the maximum likelihood estimators of the unknown parameters and also provide their exact distributions. Based on the exact distributions of the maximum likelihood estimators exact confidence intervals can be obtained. Asymptotic and bootstrap con- fidence intervals are also provided for comparison purposes. We further consider the Bayesian analysis of the unknown parameters under a very flexible Beta-Gamma prior. We provide the Bayes estimates and the associated credible intervals of the unknown parameters based on the above priors. We present extensive simulation results to see the effectiveness of the proposed method and finally one real data set is analyzed for illustrative purpose.

On generalized progressive hybrid censoring in presence of competing risks

Industrial Engineering Journal

Teaching Linear Programming

In this paper, we address various types of two-person stochastic games—both zero-sum and nonzero-sum, discounted and undiscounted. In particular, we address different aspects of stochastic games, namely: (1) When is a two-person stochastic game completely mixed? (2) Can we identify classes of undiscounted zero-sum stochastic games that have stationary optimal strategies? (3) When does a two-person stochastic game possess symmetric optimal/equilibrium strategies? Firstly, we provide some necessary and some sufficient conditions under which certain classes of discounted and undiscounted stochastic games are completely mixed. In particular, we show that, if a discounted zero-sum switching control stochastic game with symmetric payoff matrices has a completely mixed stationary optimal strategy, then the stochastic game is completely mixed if and only if the matrix games restricted to states are all completely mixed. Secondly, we identify certain classes of undiscounted zero-sum stochastic games that have stationary optima under specific conditions for individual payoff matrices and transition probabilities. Thirdly, we provide sufficient conditions for discounted as well as certain classes of undiscounted stochastic games to have symmetric optimal/equilibrium strategies—namely, transitions are symmetric and the payoff matrices of one player are the transpose of those of the other. We also provide a sufficient condition for the stochastic game to have a symmetric pure strategy equilibrium. We also provide examples to show the sharpness of our results.