NMD Registry
=============
The NMD Registry section defines the conceptual model for several key entities that play a crucial role in
the management and the assessment of the environmental impact of construction products or
processes.


.. product-card:

.. note::  Product Card is a term previously used in the NMD-systems, but now deprecated. This entity is the combination of
    :ref:`construction-product-or-process` and :ref:`environmental profile`. During the redesign in 2023, the Product Card has been
    divided in two entities, to make the entity model more descriptive and more scalable in the future.


.. contents::


.. graphviz:: conceptual-model-registry.dot
    :caption: Schematic overview of conceptual model zoomed at registry
    :name: conceptual-model-schematic-registry


Environmental Data
#####################

The NMD stores :index:`Environmental Data` in the form of environmental impact values. These values are defined
per Impact Module and per :ref:`Environmental Impact Indicator`. Using these values :ref:`Calculation tools` can
calculate the MKI and the MPG.

The recorded Environmental Data is dependent on an :ref:`Assessment Strategy`.
Different :ref:`Assessment Strategies<assessment strategy>` can be defined. At this moment of writing,
two strategies exists:  'Strategy A1' and 'Strategy A2'. These strategies have a deviating set of
:ref:`Environmental Impact Indicators <Environmental Impact Indicator>` and a deviating
:ref:`weighing vector`.


Environmental Profile
############################################

An Environmental Profile holds a collection of `Environmental Data`_, one for each obliged :ref:`Assessment Strategy`.
The profile records supplementary information on how the data was collected and how the profile should be applied.
For instance how to scale the profile.

.. note::

    In earlier versions of the NMD it used to be possible to define a *quantity* for a profile, which describe how
    many times the Environmental Profile should be applied within a product. This quantity did not add value to
    the profile. It created confusion and was prone to error. Therefore the quantity is now deprecated.
    For backwards compatibility, the quantity of profiles are set to one for new declarations.


.. _environmental-declaration:

Environmental Declaration
##########################

The Environmental Declaration contains a complete set of one or more :ref:`Environmental Profiles <environmental profile>`
describing the environmental impact of the `Construction Product (or process)`_. The Environmental
Declarations are used to calculate the :ref:`Environmental Performance of Construction Works`.

Each declaration has activation date and might have a deactivation date.

.. _environmental-declaration-version:

Environmental Declaration Registration
#########################################

The Environmental Declaration Registration is the formal registration of an :ref:`environmental-declaration`. Each Registration
has its own unique registration number. A Registration has at least one declaration connected to it. Through time,
new versions of the declaration might be released. The registration number
will remain the same, but the old declaration will become inactive and the new declaration is activated.


.. _construction-product-or-process:

Construction Product (or process)
############################################

The Construction Product (or process) is a product or process that can be applied or incorporated in
a :ref:`Construction Work`. A Construction Product always has one :ref:`environmental-declaration` connected to it and
also the other way around.


Classification
############################################

For both indexation and comparison it's important to classify :ref:`Construction Products (or processes)<construction-product-or-process>`
based on the :ref:`Classification Systems` used in the NMD. A product can have one
or multiple classifications based on the functions it fulfils in a construction.