Ramakrishnan Ramanathan

ABC inventory classification with multiple-criteria using weighted linear optimization

Inventory classification using ABC analysis is one of the most widely employed techniques in organizations. The need to consider multiple criteria for inventory classification has been stressed in the literature. A simple classification scheme is proposed in this paper using weighed linear optimization. The methodology is illustrated using an example.

Data envelopment analysis for weight derivation and aggregation in the analytic hierarchy process

Data envelopment analysis (DEA) is proposed in this paper to generate local weights of alternatives from pair-wise comparison judgment matrices used in the analytic hierarchy process (AHP). The underlying assumption behind the approach is explained, and some salient features are explored. It is proved that DEA correctly estimates the true weights when applied to a consistent matrix formed using a known set of weights. DEA is further proposed to aggregate the local weights of alternatives in terms of different criteria to compute final weights. It is proved further that the proposed approach, called DEAHP in this paper, does not suffer from rank reversal when an irrelevant alternative(s) is added or removed.

Operations assessment of hospitals in the Sultanate of Oman

Purpose – The importance of health care is growing world‐wide, and the health sector is receiving a good proportion of public funds. As health‐care costs are increasing, efforts have been made to assess the operational efficiency of hospitals in many countries.Design/methodology/approach – In this paper, the efficiencies of operation of 20 hospitals in the Sultanate of Oman are evaluated using Data Envelopment Analysis (DEA). The hospitals selected are Regional and Wilayat hospitals under the Ministry of Health, the Sultan Qaboos University Hospital and the hospital of the Royal Oman Police. Four outputs representing out‐patient visits, in‐patient services and surgical operations, and three inputs representing the number of beds and manpower are used in the analysis.Findings – Using data for the year 2000, ten of the 20 hospitals are found to be efficient. A ranking of performance of efficient hospitals has been provided by computing their super‐efficiency scores. The patterns of efficiency changes over t...

Stocking and discounting decisions for perishable commodities using expected profit approach

Purpose – Commodities that have a fixed useful life are said to be perishable commodities. These commodities pose special problems to retailers and distributors as these have to be sold before their shelf‐life. Retailers offer discounts on perishable products nearing their shelf‐lives to encourage consumers to buy. In these situations, retailers would like to know when they should begin to offer the discount, what should be the quantum of discount, and how many units of the commodity they should stock on the shelf to maximize their expected profit. This paper aims to address these three issues.Design/methodology/approach – A recently published paper has suggested a simple procedure based on expected profits to identify time and quantum of discount for perishable products. Extending this, a modified empirical procedure is suggested in this paper to identify the number of units to be stocked, discount period and the quantum of discount. A numerical illustration is used to explain the steps involved in the p...

Short Communication: Selecting the best statistical distribution-a comment and a suggestion on multi-criterion evaluation

An interesting new approach for selecting a distribution to describe the observed data has been presented in a paper recently published in Computers and Industrial Engineering. While appreciating the new contribution of the paper, we highlight an important difficulty with their method and suggest that data envelopment analysis (DEA) could be advantageously used to improve the multi-criterion evaluation.

A Study of the Patterns of Production and Consumption of Crude Oil and Petroleum Products in the Sultanate of Oman

The patterns of production and consumption of crude oil and petroleum products in the Sultanate of Oman over the period of 1970–2000 are studied in this article. A graphical description of the patterns is first presented. Simple and more sophisticated econometric models are then employed to empirically examine the relationships between petroleum-related variables and other macroeconomic variables. The analysis shows many interesting features of the behavior of crude oil and petroleum products in the Sultanate of Oman, including the following: crude oil production remained relatively stagnant until the early 1980s, but started to rise more rapidly since then. The pattern of consumption of petroleum products in the year 2000 showed a very marked difference from the consumption patterns of 1970s. Gasoline consumption grew very rapidly in the Sultanate of Oman, with a high compound annual growth rate of nearly 13%. The consumption of Regular90 variety was relatively stagnant compared to the rapid increase in the consumption of Super97 variety. The vehicular population grew at a high rate of nearly 12% per annum during the last few decades. The empirical econometric analysis has shown that the gross domestic product (GDP) and crude oil prices of the current as well as the previous year have been significant variables influencing crude oil production of any given year. The GDP is strongly related to crude oil exports, total petroleum consumption, and gasoline consumption. However, prices are not highly significant. Crude production is highly correlated to natural gas production.