Why a tracked entity needs to have an org unit for registration?

Support - Assistance technique
1

Hi, I’m learning about all the API endpoints and the design of the Tracker, and I cant understand two things:

  1. Why a Tracked entity instance needs to be created linked with an org unit?
  2. if I register a TEI and enroll it into a program for a particular orgUnit, should I create another TEI if I want to enroll it on another program for another orgUnit? I cant see from the Tracker UI how can do that

I’m using Postman for make a POST to /api/trackedEntityInstances with a payload without orgUnit and I see an error due to that.

My use case is a custom webapp that provides Q&A and Care for patients, some of the care received will be phisically on a facility ( AKA OrgUnit ), but some other care could be virtual, and we need to post the information to the tracker, so we are investigating and learning about the DHIS2 and Tracker

Thanks in advance

2

If I understood your use case very well.
As a general, three things 1. When ( Period) , 2. What (data) and 3.where (orgunit) is must either to record data in DHIS2 or extract data.

For the scond question: if you create a TEI in one orgunit for a program. You can refer it to another orgunit within the same program or create a new one.

Basically, if its another program and another orgunit, you have to create a new TEI. Or, if two programs have a relationship, you can link two program within the same orgunit.

I hope the explanation is helpful.
Good Luck