# openBIS Data Modelling

## Overview

openBIS has the following data structure:

1.  **Space**: entity with *Code* and *Description*. Access can be controlled at this level.
2.  **Project**: entity with *Code* and *Description*. Access can be controlled at this level.
3.  **Experiment/Collection:** entity with *user-defined properties*.
4.  **Object**: entity with *user-defined properties*. 
5.  **Dataset**: folder where data files are stored. A dataset has *user-defined properties*.      
      
![image info](img/openbis-data-model-v3.png)


*Space* is the top level. Below *Spaces* there are *Projects* and below *Projects* there are *Experiments/Collections*. 
In the general openBIS data model, *Objects* can:
- be shared across *Spaces* (i.e. they do not belong to any Space)
- belong to a *Space*
- belong to a *Project*
- belong to an *Experiment/Collection*
  
*Datasets* can be associated only to *Experiments/Collections* or to *Objects*.  

Access to openBIS is controlled at the *Space* level, *Project* level or openBIS instance level (see [openBIS roles ](../general-admin-users/admins-documentation/user-registration.md#openbis-roles)).

  

## Data model in openBIS ELN-LIMS 
-------------------------------

In openBIS 20.10.12, restrictions to the openBIS data model in the ELN-LIMS have been lifted, with the exception that shared Objects are not used.  


![image info](img/201012-openbis-ELN-data-model.png)



## Inventory

The inventory is conceived to be shared by all lab members. The
inventory is used to store all materials and protocols (i.e. standard
operating procedures) used in the lab. It is possible to create
additional inventories, for example for instruments and equipment.

The picture below shows an example of an Inventory with the different openBIS levels.  

![image info](img/201012-data-modelling-inventory-mapping.png)


In the Inventory we recommend to continue using the *Space*/*Project*/*Collection* hierarchy, because *Collections* provide a tabular overview of objects, which would be missing if *Objects* were created directly under a *Space* or *Project*.


## Lab Notebook

By default, the lab notebook is organised per user. Each user has a
personal folder (=*Space*), where to create *Projects*, *Experiments*
and *Objects*. Data files can be uploaded to *Datasets*. Example structure:

  
![image info](img/201012-data-model-labnotebook-mapping.png)



  

Some labs prefer to organise their lab notebook using an organization
per project rather than per user. In this case an openBIS *Space* would
correspond to a lab Project and an openBIS *Project* could be a
sub-project or a user folder (one folder per user working on the same project). 
  

## openBIS parents and children
----------------------------

*Objects* can be linked to other *Objects*, *Datasets* to other *Datasets* with
N:N relationship. In openBIS these connections are known as *parents*
and *children*.

  

![image info](img/objects-parents-children.png)![image info](img/dataset-parents-children.png)



  

## Examples of parent-child relationships

1.  One or more samples are derived from one main sample. This is the
    parent of the other samples:  


![image info](img/sample-vials.png)
      
2.  One Experimental step is performed following a protocol stored in the
    inventory, on a sample stored in the inventory, using a given equipment. The protocol, the sample and the equipment are the parents of the Experimental step


![image info](img/exp-step-parents.png)

      
3.  One Experimental Step is done after another and we want to keep
    track of the links between the steps: 
    
     
![image info](img/exp-step-parents-children.png)