# Actor grouping examples - Medication Prescription and Dispense (MPD) v1.0.0-comment-3

* [**Table of Contents**](toc.md)
* **Actor grouping examples**

## Actor grouping examples

The actors illustrated the [actors and transactions](actors-transactions.md) can be grouped in different architectures.

This page provides some examples with some information on how this can be specified.

### Central prescription repository

In the central prescription repository, the order placer communicates the prescriptions with a central prescription repository (which therefore implements the specification (actors) of Order Receiver and Order Responder). Similarly, the Order Consumer consults that repository for checking which prescriptions are available and to fetch the information of those prescriptions.

### Pull model

In the Pull-Based Architecture, the Order Placer is integrated with the system that holds the prescriptions. When a healthcare entity (acting as an Order Consumer) needs to access a prescription, it explicitly pulls the information from the Order Responder using an on-demand query.

### Push model

In a Push-Based Architecture, the Order Placer submits a medication order that is immediately pushed to the Order consumer. This is akin to messaging.

### Ordering flows

The same actors can be used for ordering workflows, for example when orders need to be send for review by another entity, and that entity then acts as a placer for the updated order.

