Goal Attainment Scaling (GAS)

Introduction

The Petroleum & Geothermal Group of Primary Industries and Resources, South Australia (PIRSA) is moving away from prescriptive legislation to an objective based system.

For objective-based regulation to be effective, a means for establishing explicit objectives and criteria for measuring and reporting on the attainment of those objectives is a mandatory requirement.

The Petroleum & Geothermal Group of PIRSA proposes that such a means can be facilitated through the use of a tool known as Goal Attainment Scaling (G.A.S).

Thus far G.A.S has been extensively trialed by PIRSA and Santos Ltd in assessing the rehabilitation objectives of abandoned petroleum well sites and seismic lines in sand dune and floodplain landsystems of the Cooper Basin in the northeastern corner of South Australia.

G.A.S. was introduced by the Petroleum & Geothermal Group to the broader industry for the first time at the Minerals Council of Australia 20th Annual Environmental Workshop in Darwin in 1995.

A number of other mining companies are also trialling the use of G.A.S including the ETSA Corporation in coal field rehabilitation and Western Mining in their Olympic Dam drill site rehabilitation program.

Goal Attainment Scaling - Theory

Definitions for common rhetoric used in G.A.S are offered in Table 1.

Table 1 - Key Definitions

Objectives

Broad statements of desirable achievements.
For example, in terms managing environmental impacts, objectives may include:

  • "minimise impact on soil"
  • "minimise impact on vegetation"
  • "minimise visual impact"
Goals Declaration of desired results for any activity. When all of the goals have been attained the objective is considered to be achieved.
For example, a goal for the objective to "minimise impact on vegetation" may be: "regeneration of vegetation achieved after 2 major rainfall events or 5 years after abandonment".
Outcomes These are measurable results which are likely to be achieved by the activity and are used to determine whether a goal has been achieved. For example, one measurable result for assessing the level of achievement of the environmental goal: "regeneration of vegetation achieved after 2 major rainfall events" could be: "vegetation type and density indistinguishable from the surrounding landscape". Outcomes are used to assess the level of goal attainment and hence the achievement of the objective.

An important feature of G.A.S is that for any goal (whether it be environmental or otherwise) stakeholders are involved in evaluating and seeking consensus on the most important aspects of the goals to be achieved within a particular timeframe and the likely range of desirable and undesirable outcomes of the activities undertaken within such a timeframe. The technique forces participants to document in an unambiguous way the expected outcomes ranging from the more to the less favourable. The various levels of outcomes can take the form of descriptive statements, statements supported by photographs or quantitative data. Each outcome level is rated in respect of the chance it has of occurring, as described in Table 2.

Table 2 - Likely Outcome Levels for any Goal 

Rating Level  Outcome  Description
-2 Very unsatisfactory level for attainment of goal. Lowest probability of occurring.
-1 Unsatisfactory attainment of goal. Lower probability of occurring.
0 Minimum desirable level of attainment Highest probability of occurring.
+1 More favourable level of attainment. Lower probability of occurring.
+2 Ideal level of attainment Lowest probability of occurring.
Continual Improvement

G.A.S is a dynamic concept, in other words the goals and measurable outcomes defined can be subject to continuous review and assessment so as to ensure that changing circumstances are not overlooked. That is, it recognises that the definition of environmental goals and their respective desirable and undesirable outcomes are based on the best available information at hand at the time these are defined. With new information coming to hand and with improvements in technology these goals and outcomes can be reviewed.

Graphical Indicator

The quantitative representation of qualitative data, makes G.A.S an effective means for simple assimilation of the environmental situation in relation to any goal at any point in time. Over time we would expect to see a skew toward the +2 outcome for each goal.

Environmental Management Systems (EMSs)

One of the requirements of objective regulation is for industry to develop management systems designed to achieve goals and objectives. It would be necessary for such management systems to be integrated into the regulatory regime with regard to goal setting, reporting and auditing.

An environmental management system includes both internal and external audits to check compliance with procedures and achievement of goals and objectives as well as reporting to the regulator. In relation to auditing and reporting the achievement of environmental goals, G.A.S can be integrated into the environmental management system (EMS) to support these processes.

A management tool such as G.A.S fits into the goal and target setting and the checking and corrective action elements of an EMS to ensure that desirable environmental outcomes are achieved (Figure 2).

Figure 2: A model showing the core elements of an environmental management system integrating the concept of G.A.S. (as adapted from ISO/CD 14001.1 Revision and ISO 9001:1994)

enviro_gas_fig5

Examples

To illustrate the preceding discussion, the results from the trials undertaken are presented in the following paper "Goal Attaining Scaling : Environmental Impact Evaluation in the Upstream Petroleum Industry" and a guideline for using G.A.S. on wellsites in the Cooper Basin is provided in the "Field Guide for the Environmental Assessment of Abandoned Petroleum Wellsites in the Cooper Basin, South Australia".