Concepts
========

Within this document, we will discuss the central concepts of the ENLYZE platform and
understand their relation to one another.

.. _site:

Site
----

The concept of a *site* refers to a physical production site. Depending on its size,
your organization might have one or many of them. In the ENLYZE platform, each site has
a name and an address, which makes it easy to identify for humans.

.. _machine:

Machine
-------

A *machine* refers to a machine that your organization uses to produce goods. For
example, a CNC-milling center, a blown film extrusion line or an injection molding
machine all represent a machine in the ENLYZE platform. Just as a physical machine is
located at one production site, a machine in the ENLYZE platform is associated with
exactly one :ref:`site <site>`.

.. _variable:

Variable
--------

A *variable* represents a process measure of one :ref:`machine <machine>` of which
timeseries data is captured and stored in the ENLYZE platform. One machine may have many
variables, whereas one variable is only associated with one machine.

.. _production_order:

Production Order
----------------

A *production order* represents the goal of producing a certain quantity of a given
:ref:`product <product>`. This is how operators know how much of which product to
produce. Production orders are usually created in an external system such as an ERP or
MES and then synchronized into the ENLYZE platform. They are referenced by an identifier
which oftentimes is a short combination of numbers and/or characters, like FA23000123.

In the ENLYZE platform, a production order always encompasses the production of one
single :ref:`product <product>` on one single :ref:`machine <machine>` within one or
more :ref:`production runs <production_run>`.

.. _production_run:

Production Run
--------------

A *production run* is a time frame within which a machine was producing a :ref:`product
<product>` on a :ref:`machine <machine>` in order to complete a :ref:`production order
<production_order>`. A production run always has a beginning and, if it's not still
running, it also has an end.

Usually, the operator of the machine uses an interface to log the time when a certain
production order has been worked on. For instance, this could be the machine's HMI or a
tablet computer next to it. In German, this is often referred to as
*Betriebsdatenerfassung* (BDE). It is common, that a production order is not completed
in one go, but is interrupted several times for very different reasons, like a breakdown
of the machine or a public holiday. These interruptions lead to the creation of multiple
production runs for a single production order.

.. _product:

Product
-------

A *product* is the output of the production process which is executed by a :ref:`machine
<machine>`, driven by a :ref:`production order <production_order>`. In the real world, a
machine might have some additional outputs, but only the main output (the product) is
modeled in the ENLYZE platform. Similarly to the production order, a product is
referenced by an identifier originating from a customer's system, that gets synchronized
into the ENLYZE platform.

During the integration into the ENLYZE platform, the product identifier is chosen in
such a way that :ref:`production runs <production_run>` of the same product are
comparable with one another. This is the foundation for constantly improving the
production of recurring products over time.