Difference between revisions of "Entity Data Model"

Revision as of 14:27, 18 December 2012

Introduction

Objectives

In an industrial environment we quite often need to

• describe an industrial plant consisting of a bunch of different parts, each having a certain purpose and set of properties, and which are related in various ways
• manage process or maintenance data of the plant and its features
• do a high-performance cost-benefit analysis and create key performance indicators

Therefore we need to

15 px „Dissemble“ the system into theoretical blocks representing the real as well as intangible parts of the system.
15 px Identify the necessary properties of the blocks.
15 px Think about how blocks are possibly related to each other.
15 px Think about the functions and features of blocks.

Plant picture

Lets start with a simple picture and assume that our plant consists of a pump and an armature. Both equipments exhibit certain technical or other properties, which our datamodel must contain in some form. Additionally the datamodel has to provide mechanism to indicate the circumstances that both equipments are parts of the plant and maybe even be related to each other.

For our first example plant, the pump and armature we find the following definitions

Looking closer at the "PUMP" block reveals its properties and property values

Of course, a real plant consists of multiple pumps, each described with the same set of properties (TAG, vendor, power, maintenance data). The real pumps in the plant are distinguished by different property values as given in the table.

We can redefine or extend our objectives by

From the plant picture to UBIK

Transition

In summary we can picture the transition from the plant picture into an object- / data-model like

and post our first definition

Intermediate summary I

Up to now we have 20 px Theoretical blocks representing the parts of the system

20 px Identify necessary properties of the blocks

20 px How are the blocks (=metaclasses) related to each other?