Activities that have a special level of service between each instance of an activity are heterogeneous and termed supplied activities. The ability to realise the activity varies substantially between each instance of the activity. ‘Places of employment’ is the only core+ activity identified as meeting this criterion.
Weighting the accessibility score similar to the consumed activities based on the order in which supplied activities are reached (using a harmonic series) is not appropriate in this instance. Instead, it is preferable to total the number of (co-located equivalent) positions within an acceptable travel range to determine the accessibility to employment. Therefore, for places of employment, the (λ) parameters for each path are summed to provide the accessibility measure. The value of the indicator is then an ever-increasing value that recognises that saturation of opportunities is not reached.
It is not possible to compare the consumed and supplied activities because although the basis for the calculations is the same, the way they consider multiple opportunities and saturation of opportunities is significantly different. For this reason it is also not possible to include both the supplied and consumed elements for an aggregated indicator. Combining the supplied and consumed indicators to one aggregated score requires further research including reviewing the way supplied activities are measured and possible saturation values.