The mission of the ESSArch Digital Archive Concept is to provide an open source based solution for long-term preservation of digital information. It is cost effective, reliable, storage independent and easy to integrate into your existing environment. It is based on well known open standards and methods.

Why ESSArch?

• Cost effective – is an open source based solution for long-term preservation of digital entitys
• Storage independent - can store digital archival entitys in any type of storage such as Tape librarys, SAN disksystem, Object based storage (CAS, storage cluster cloud) among other storage architectures
• Easy to integrate – can easily be integrated with existing archival information systems
• Reliable - guarantees that all files deposited by agreement with its affiliates remains authentic,  available, unaltered, and readable from media.
• Based on open standards and methods – OAIS, METS, PREMIS, MIX among others …
• Licensed GPLv3

	Negotiations between producers and the archive management results in agreements for preservation principles, technical tolerances, package structures, processes and regulations. It also identifies, defines and quantifies organisational needs as well as how everything should be financed. Delivery from this function is a Submission Agreement and requirements interpreted into preservation planning and regulations management.
	PreIngest is the function used to prepare packages for delivery according to Submission Agreement. Unstructured information becomes structured.
	Ingest provides services for receiving submission information packages (SIP), quality checks and preparation for delivery of archival information packages (AIP) to storage infrastratucture. Ingest also updates data mangament in order to prepare for preservation and administration routines as well as for retrievel capabilities.
	Access provides services for receiving and resolving inquiries from Consumers. It fetches Archival Information Packages (AIP) and creates Dissemination Information Packages (DIP) if required and performes quality checks before delivery to PreAccess function.
	PreAccess provides capabilities to adjust Dissemination Information Packages (DIP) or any result sets required from Consumers into agreed structure stated in Submission Agreement.
	If needed and not stated in Submission Agreement a negotiation concerning Access and PreAccess requirement will accour in a similar manner as with the producer and with the same outcome, a Submission Agreement for retrievel. The overall performance from archival management are measured and followed up and any deviations are taken care off.

ESSArch - the platform

• ESSArch is a practical implementation of OAIS (Reference Model for an Open Archival Information System) and includes PreIngest, Ingest, Data Management, Archival Storage, Access and PreAccess. ESSArch is managed by Archive Management and Management Regulations
• ESSArch is a Python application designed to run in a Unix/Linux environment.
• ESSArch uses METS (Metadata Encoding and Transmission Standard) descriptors for all information packages. METS is an XML document format. More information about METS is available from the Library of Congress
• ESSArch uses PREMIS (Preservation Metadata and Maintenance Activity) together with METS to describe events and technical metadata for datafiles. More information about PREMIS is available from the Library of Congress
• ESSArch uses HTTP (HyperText Transfer Protocol) as one interface to communicate with thru a traditionell web reader
• ESSArch uses XMLRPC (XML Remote Procedure Call) as another interface to communicate with ESSArch
• ESSArch also uses W3C SOAP (Simple Object Access Protocol) as another communication interface
• ESSArch is built upon MySQL databases where ESSArch stores information to manage the information packages. 
• ESSArch contains several storage methods where ESSArch stores the information packages. ESSArch can natively write to a Unix filesystem or a Tape library. In future release it is planned to support Object based storage (CAS, storage cluster cloud)