Are the Criteria Weighted?
Project Development criteria are weighted according to their impact on sustainability and the duration of that impact.
INVEST applies weighting for the Project Development (PD) criteria only as described in the sections that follow. The criteria in the System Planning modules (SPS and SPR) and the Operations and Maintenance (OM) module are all equally weighted at 15 points (except the bonus criterion in each SPS and SPR which is valued at 10 points). Within each of these criteria, the points are distributed to different scoring requirements using an effort-based approach. That is, scoring requirements that require more effort are worth more points than those taking less effort.
The Goal
The overall goal of weighting is to make the point value for each criterion commensurate with its potential to affect sustainability both in terms of significance and duration of the impact.
Why Weight Criteria?
When using a set of criteria to evaluate performance toward meeting a goal, a key question is the extent to which the criteria are equally important in meeting that goal. If the criteria are of unequal importance, the measures of success can be improved by weighting the relative importance of the criteria. When assigning weights, the contribution to sustainability achieved from the worst likely outcome to the best likely outcome for one criterion should be compared to another. In other words, larger weights are assigned to criteria that are likely to have the largest impact on sustainability from project to project.
Examples in Weighting
As an example, envision two projects: one in which best-in-class environmental training is provided versus another where no environmental training is provided. The difference in sustainability likely to occur from that criterion is likely to be small (because training does not necessarily result in action), thus that criterion should be assigned a relatively low weight. Now envision two other projects: one in which best-in-class long-life pavements are designed and implemented, and another in which they are not. Here the difference in sustainability associated with that criterion is likely to be substantial due to the cumulative benefits achieved over the project lifecycle Therefore, that criterion should be assigned a relatively high weight.
Next > System Planning
