Showing papers on "Productivity model published in 1991"

A model to evaluate variables impacting the productivity of software maintenance projects

Abstract: The cost of maintaining application software has been rapidly escalating, and is currently estimated to comprise from 50-80% of corporate information systems department budgets. In this research we develop an estimable production frontier model of software maintenance, using a new methodology that allows the simultaneous estimation of both the production frontier and the effects of several productivity factors. Our model allows deviations on both sides of the estimated frontier to reflect the impact of both production inefficiencies and random effects such as measurement errors. The model is then estimated using an empirical dataset of 65 software maintenance projects from a large commercial bank. The insights obtained from the estimation results are found to be quite consistent for reasonable variations in the specification of the model. Estimates of the marginal impacts of all of the included productivity factors are obtained to aid managers in improving productivity in software maintenance.

Productivity Growth in U.S. Agriculture under Dynamic Adjustment

Abstract: A dynamic measure of productivity growth adjusted for deviations from the long-run equilibrium is established within an adjustment-cost framework. An empirical application to U.S. agriculture is presented which permits identifying the dynamic linkages between technical change and productivity growth in U.S. agriculture. Total factor productivity as dynamically measured grew at 1.50% per annum. The combined effect of scale, quality-adjusted input growth, and long-run disequilibrium input use contributes only 3.44% of the growth, while technical change dominates the growth of total factor productivity.

Modelling the effects of motion on primary production in the mixed layer of lakes

Abstract: A model of the time dependent relationship between productivity and light intensity following changes in light intensity is briefly described. The model incorporates two response timescales simulating initial response and photoinhibition, although additional timescales could easily be incorporated. The model is calibrated against one set of time dependent data, and applied to two simple models of motion in the upper mixed layer of a lake. The two models are: organised motion simulating Langmuir cells, and disorganised motion simulating the turbulent velocity field associated with surface wind stirring. The depth and therefore light histories for a number of photosynthesising particles are calculated by these models, and used by the productivity model to calculate mean productivities. The results show that the influence of the time dependent nature of the productivity relationship depends on the ratio of the mixed layer depth to the euphotic depth, and to a less extent, on the rate at which the particles circulate in the mixed layer.

Model of software effort and productivity

Abstract: A new model of software effort and productivity is described, wherein the estimated productivity of an organization is equal to the average productivity modified by a function of the cost factors. Techniques for generating the cost multiplier associated with each cost factor are shown, and equations are derived for calculating the effect of combinations of cost factors. A key characteristic of the model is its ability to amortize the cost of a factor over the projects that may be affected by the factor; thus the model allows assessment of the cost of reuse. The quality of the model is evaluated by examining its predictive accuracy. It is shown that on a test set of object-oriented projects where size is measured by number of objects and methods, the new model shows greater promise than COCOMO and Ada-COCOMO.

Estimating Productivity Changes with Flexible Coefficients

Abstract: Technical progress in U.S. agriculture is evaluated using a new measure of productivity growth, flexible technical change. This measure allows for nonconstant returns to scale, market structures other than perfect competition, and time-varying coefficients. An integral part of the procedure is the estimation of the production function by Flexible Least Squares. Flexible technical change results are compared with two traditional measures of productivity growth and found to be more stable and more precise in a statistical sense. The results suggest that previous studies which employed total factor productivity measures may have overstated the impact of

Productivity and metal mining: evidence from copper-mining firms

Abstract: One of the aims of productivity measurement is to assess the performance of various sectors of the economy with respect to their use of scarce inputs. In this paper the emphasis is on the effects of firm behaviour on simple index number measurement of total factor productivity in non-renewable resource industries. Economic theory predicts that when the stock of ore is known and there is positive discount rate, an intertemporally profit-maximizing firm will often process the ‘best’ ore first. That is, ores that are of high grade and/or are most easily accessible will be correspond to the lowest-cost units of final metal output. Less capital, labour, energy and matgerials will be needed in the mining and milling processes.

Productivity measurement and management at the company level : the Japanese experience

Abstract: Parts: I. Concepts of Productivity. 1. Productivity as a guiding principle of the productive force/activity of the human race. 2. Structure of company productivity. 3. Bird's-eye view of productivity at the company level. II. Productivity Indices. 4. A general introduction to productivity index number analysis. 5. Index number system/ratio system for planning and management of productivity. 6. Unit input requirement management and measurement system. 7. Hierarchical weighted average labour productivity index number system with variable structure: The HW LAP system. III. Worker Productivity. 8. Some considerations on the relationship between worker productivity and the intensity of labour. 9. Foundations of worker productivity management and measurement. 10. Analysis of output per man-hour. 11. Workshop productivity management by ratios - The WPMR system. IV. Total Productivity. 12. Measurement and analysis of total productivity and profitability: The AIPR system. 13. Productivity index in terms of nominal prices - Total productivity by the equivalent labour unit method. V. Added Value Productivity. 14. Fragment - Structure constructed from variants of the productivity and the added value. 15. Added value productivity in an enterprise. 16. Aggregate index for the analysis of added value productivity. 17. Measurement and analysis of the added value ratio. 18. Business accounting based on added value. Appendices: Principal component analysis. Law of added value labour productivity differentials. Conclusion. Bibliography.

The role of value added in benefit/cost analysis

Abstract: The problem is to determine the role of value-added information in obtaining a measure of the benefits of public investment. Net benefit in a benefit/cost analysis is the change in economic surplus, i.e., the sum of the increase in consumer surplus and economic rent. An increase in productivity causes an increase in economic surplus. Thus, a productivity index is necessary but not sufficient information needed to measure the change in economic surplus. Information on value added can be used to establish productivity. Diewert's quadratic lemma is used to derive an index of productivity as the difference between indexes of value added and its primary components in the context of a non-homothetic production function. It is concluded that this same procedure should be used to measure productivity in either a taut or a slack economy.

Relative value units: practical productivity measurement.

Abstract: The relative value system of measuring productivity can be an effective measurement tool for radiology administrators if properly designed and implemented. Since the financial future of the health care industry continues to dominate both private and public agendas, qualitative measurements of health care delivery alone will not suffice. Even if the relative value system is not the ultimate panacea for evaluating productivity, it is at least one reasonable method of attempting to address the issue of quantitative measurement of radiology services. This article will introduce relative value units (RVUs) as a practical method of measuring productivity in the radiology department.

Including capital input within total productivity measurement

Abstract: In an environment of inflationary conditions and rapid technological change, the state of the art of total productivity measurement is reviewed—focusing on the importance of capital input along with the more common materials and labor factors. The basis for capital input measurement is discussed and evaluated, including the concepts of economic, deprival, replacement, and net realizable values. The weaknesses of using historic cost are considered and a replacement cost system is elaborated with the capital input shown at base-year prices. Examples are provided to illustrate how a more relevant measure of capital input can help improve strategic decisions based on total productivity.

The structure of production, technical change and total factor productivity in the northern ireland agricultural industry, 1955–86

Abstract: This paper presents an empirical investigation of the structure of production in N. Ireland agricultural industry. A flexible (translog) cost function model is estimated to obtain measures of neutral and non-neutral technical change, substitution between factor inputs, and economies of scale. The cost function model is also utilized to decompose Tornqvist productivity gains into the contributions due to technical change, scale economies, and other (residually measured) influences. This decomposition analysis provides useful estimates of the extent to which productivity growth has been hindered by the small scale of N. Ireland farms and the extent to which this has been offset by technical change. Copyright 1991 by Scottish Economic Society.

Output mix changes and labour productivity in greek manufacturing

Abstract: A simple method to quantify the effect of changes in the output mix on labour productivity is presented and implemented to the Greek manufacturing sector. Although data unavailability prevented us from identifying the full output mix effect, the results of the analysis point to the conclusion that a non-negligible part of the rise in productivity over the last 20 or so years may have been caused by shifts of the output mix in favour of products requiring less manpower.

Target: increased productivity exploratory eastern European model

Abstract: The author proposes a novel approach to productivity model building. The concept is based on integrating component parts of existing eastern (Japanese) and western (American) models for possible use in the Soviet Union and other eastern European countries. It attempts to bridge cultural and traditional differences so as to present a model that is adaptable to varying economic conditions and external environments. The proposed model is basically a dichotomy utilizing a Nenko system type foundation and an open, mobile, managerial class superstructure. >

Measuring Energy Input, Quality and Productivity

Abstract: In this paper, we discuss and compare two specific energy aggregates, the Divisia and Btu indexes. These indexes are constructed using disaggregate data on 12 types of energy used in 72 industries to the total U.S. manufacturing level for the period 1958-1981. We then compute and analyze different effects contributing to the growth in energy input and energy productivity. Our results show strong evidence that energy aggregates constructed by different methods result in significantly different energy productivity growth rates. The Divisia index gives more satisfactory results than the Btu index.