data envelopment analysis data envelopment analysis

Refers to an inefficient DMU’s composite unit to emphasise that geometrically it involves the projection of the inefficient DMU onto the efficiency frontier (Ali and Seiford 1993). [Ali A and Seiford L (1993), ‘The mathematical programming approach to efficiency analysis’, in: Fried H, Knox C A K and Schmidt S (editors), The measurement of productive …

Continue reading

For a single input-output case, the ratio of a unit’s output to its input. Productivity varies according to changes that occur in the production technology, the efficiency of the production process (which can be measured through DEA) and the production environment (Lovell 1993). [Lovel C A K (1993), ‘Productive frontiers and productive efficiency’, in: Fried …

Continue reading

Given a set of inputs that produce outputs, the production function defines an optimum relationship for producing the maximal amount of output from the given inputs. The DEA equivalent of the production function is the efficiency frontier which is based on empirical data (inputs and outputs). See Chames et al (1981) for details and more …

Continue reading

The primal model allows the DMU being measured to determine the set of optimal weights for each of its factors (outputs are denoted by y. and inputs by x in the following model) so as to maximise its efficiency. The solution consists of a set of weights (for outputs and y for inputs) chosen so …

Continue reading

An efficiency frontier is piecewise linear when the underlying production function is approximated through interconnected linear segments. The basic DEA models are all piecewise linear. See Chames et al (1981) for implications. [Chames A, Cooper W W and Rhodes E (1981), ‘Evaluating program and managerial efficiency: an application of data envelopment analysis to program follow …

Continue reading

Another name for reference set

Simply stated, a unit is Pareto-efficient when an attempt to improve on any of its inputs or outputs will adversely affect some other inputs or outputs. Formally, Chames et al (1981) consider a DMU to be 100% efficient only when ‘none of its inputs can be decreased without either (i) decreasing some of its outputs, …

Continue reading

Same as aggregate efficiency

In an output-oriented model, an inefficient unit is made efficient through the proportional increase of its outputs, while the inputs proportions remain unchanged.

A factor which describes the amount of goods, services or other outcome obtained as a result of the processing of resources. Also, any factor which describes the qualitative nature of the resulting outcome.