Understanding Entity Relationships in SAP MDG

There are four relationship type in SAP MDG. In this blog we will discuss the first three with samples. I'll cover foreign key relationship in a later blog with an accurate sample.

But, before we proceed with the implementation, let me outline the "business scenario" that we will use to understand entity relationships:
Rental Car Sample Scenario (Why fictitious scenario?): A Rental car agency (lets call it PRITZ) buys new cars on a regular basis, to maintain/expand their fleet of cars at various rental office locations, across the country. We will create a MDG solution to maintain the master data for the cars in the fleet. When PRITZ buys new types of cars (or sells existing cars), a business user (say Lisa) in PRITZ's headquarters will use our MDG solution to add the new car types into the system. If PRITZ decides to buy 80 Toyota Prius 2019 models for 13 rental locations, Lisa will use our MDG solution to add Toyota Prius as a new car type in the system and trigger the change request process. The change request then goes through the various departments of Maintenance, Operations and Sales. Master Data Stewards at each of these department will enhance the data with the right attributes and approve them. It is also important to point out that, MDG solution is to maintain the "master data" of Car type. Every time a new purchase order is created to buy additional cars (or an existing car type), it a "transactional data" in the system.

In the reference implementation of the above scenario, we have following relationships. BTW, the entire end to end implementation of this MDG solution can be viewed here.

But, to start with, the data model will look something like this.



Leading: In our example here, it is the a relationship between a RCAR (SUType1) and SUType4 entities. The key, RCARID, of RCAR is automatically added as the key for the SUType4 generated table

Qualifying:

Referencing:

It is important to note that the MDG eLearning series is being constantly updated. It is a one time fee to get life time access to the training material and it is constantly updated to add additional MDG scenarios.

Why use a fictitious scenario rather than a real world ERP scenario?
We decided to use fictitious scenario for several reasons. We go through the entire end to end realization phase with this sample scenario for custom object. This helps showcase all the capabilities of MDG. With a ERP scenario, it would help to know the master data object well. The simple rental car business scenario is relatively very simple to grasp. A MDG beginner can spend more time focussing on the details of MDG and its underlying technologies. As opposed to getting bogged down with Material, Plant, MRP, BOM, Routing and other details.
We will cover scenarios involving MDG Material solution in later additions of the eLearning content.