The term 'sharing' data is used in different contexts. It may mean sharing data within your project team during the life of the project. However, the term is often used to mean sharing your data with the wider research community or the public. It's important to be clear about which kind of sharing you are referring to when writing data management plans.
'Open Data' is one form of data sharing. This normally refers to making data publicly available, downloadable and re-usable through a data repository such as DMU Figshare or a subject-specific repository like the UK Data Archive.
'Archiving' data means storing data for the long term. This might be either with or without public access to the data.
During, and especially towards the end of your project, you will need to make decisions about what will happen to your data after your research project is completed. Some of the elements you will need to consider are:
This process is known as data appraisal. You will have thought this through at a high level when producing your data management plan. However, you will need to carry out a detailed appraisal towards the end of the project. It is worth factoring in time and cost for carrying out this activity in your project plan and bid.
How to appraise and select research data is a useful guide from the Digital Curation Centre.
"All research data of continuing value to the researcher and/or wider research community, or specified by funding bodies or publishers, or required for legal or other regulatory purposes, must be made openly available unless restrictions apply."