(The below definitions are mainly from https://www.hl7.org/fhir)

The Measure resource provides the definition of a quality measure. While a quality measure is a quantitative tool to assess the performance of an individual or organization with respect to a specified process or outcome via the measurement of actions, processes, or outcomes of clinical care. The logic of a measure resource is usually defined in one or more library resources.

A library resource is a general-purpose container for knowledge asset definitions. It can be used to describe and expose existing knowledge assets such as logic libraries and information model descriptions, as well as to describe a collection of knowledge assets. These assets may be defined using FHIR resources or non-FHIR representations. A library resource is also intended to represent shareable knowledge independent of any particular patient.

The subject element of the Measure indicates the intended subjects of a measure. The default is Patient, but it could also be something else, like a Location or a Device.

The Measure resource has an $evaluate-measure operation which returns a MeasureReport.

The MeasureReport resource contains the results of the calculation of a measure for a specific subject or a group of subjects; and optionally a reference to the resources involved in that calculation. The resource is capable of representing three different levels of report: individual, subject-list, and summary.

In our case, in order to use these resources we would need to create measure resources which would define the indicators. We could either define a separate measure resource for all indicators, so like one for stock status and another for quantity received, or we could make the clarifications more in the definition of the library resources which would act as the logic for the measure resource.

I could not find any resource that would fit our purpose straight out of the box, but FHIR offers the flexibility of extending a resource which should work in this case. For this ticket I was mainly looking into the two resources and how they work, so I think more details would come in the next ticket which will be looking at the same resources but specifically maybe next steps for implementation.