SAP Note Assistant is a tool that helps you while working with SAP Notes. SAP Notes is a set of instructions to remove known errors from the SAP systems. Using the Note Assistant tool, SAP Notes can be applied to the system. You can access the Note Assistant tool using transaction SNOTE.  

The Note Assistant tool is now enhanced with the following new innovations:

• A new highly intuitive, integrated, and customizable Home screen.
• Streamlined SAP Notes implementation.
• The SAP Note display screen is highly informative and customizable.
• User settings offer a highly customizable experience.

The enhanced Note assistant is now available from SAP_BASIS 7.50 SP0 release and onwards. The tool is either available automatically or implemented via SAP Note 3051466.

• SAP Notes are made secure with digital signing of each SAP Note, and all SAP Notes are digitally signed SAR files.
• The download and upload process will only work if Note Assistant (SNOTE transaction) is enabled in ABAP systems to work with digitally signed SAP Notes.
• All actions required are bundled in SAP Note 2836302. For detailed understanding of each step, please refer to the PDF attached to SAP Note 2836302.

Resources:

SAP Note Transport-based Correction Instruction (TCI) is a way to deliver ABAP corrections in a flexible manner. TCI has the following advantages:

Enabling Note Assistant for SAP Note Transport-Based Correction Instructions

By default, the Note Assistant tool cannot consume TCIs, unless SAP BASIS of the ABAP system is at a certain SP level. In case ABAP system is not at the prerequisite SP level, you should enable the Note Assistant (NA) tool to consume the TCIs. To do so, you must implement relevant SAP Notes. These SAP Notes are called as bootstrap SAP Notes and differ depending on the SAP_BASIS releases.
Enabling the Note Assistant for SAP Note TCI varies for different releases. For more information please refer below links:

SAP Note Assistant tool has the following functionalities:

• Searching and Reporting: Search and download valid SAP Notes. Browse the list of downloaded SAP Notes.
• Correcting Errors: Implements the corrections included in the SAP Notes automatically. 
• Logging and Troubleshooting: All Processing steps are logged, which can be used for troubleshooting. Additional troubleshooting reports are available.
• Reporting: All downloaded SAP Notes can be viewed with their processing status, and implemented corrections.
• Integration: The system recognizes whether the SAP Notes are implemented by an imported support package or via an upgrade.