Software Development Approaches and Teaming at NSSDC

By Joseph King, Pat McCaslin, and Don Sawyer

Development of the software enabling the NSSDC data management improvements described in the other articles of this newsletter was the result of coordinated and complementary efforts of two NSSDC software groups - the DIOnAS group and the NOST group.

As NSSDC's data management requirements were emerging, NOST (D. Sawyer) and NSSDC (J. King) recognized that NSSDC's data management practices could be made more robust, and the OAIS concepts realized in a major science archive, by committing the NOST software team to work with the DIOnAS team in adapting and extending NOST's already existing prototype software to meet NSSDC needs in a mode complementary to the basic DIOnAS software. System engineering staff from both groups developed an overall system design that allowed largely independent but complementary code development efforts.

The basic DIOnAS software and database were developed by a team of a few Raytheon ITSS developers who constitute NSSDC's primary data management software team.

DIOnAS was developed in response to system requirements established by the SSDOO/NSSDC Configuration Control Board (CCB). The CCB consists of a mix of senior technical and management NASA and Raytheon ITSS personnel and is chaired by Ms. Nancy Laubenthal, the SSDOO Associate Chief. The CCB monitored DIOnAS developments through formal reviews (e.g., requirements review, design review) and status briefings at its regular meetings.

The basic DIOnAS package consists of approximately 20,000 lines of code written mostly in Java. About 12 months of effort transpired between the start of the DIOnAS effort and the operational deployment of DIOnAS in August 2000.

Key software modules called by DIOnAS were written by the NSSDC/NOST software team consisting of one Raytheon ITSS developer plus part of a system engineer. This group, guided by NSSDC's Don Sawyer (Head of NOST) and jointly funded by NSSDC and NASA's System Operations and Management Office, has for some time been developing software for implementing various aspects of the ISO/CCSDS-sponsored OAIS model.

The NOST team used object-oriented software engineering practices and generated about 25,000 new lines of mostly C code in its direct support of NSSDC and DIOnAS.

Besides the original system design and the design, coding and integration of each module, a significant effort was put into testing of these products. For example, another 5,000 lines of code were generated for testing the NOST products. Once testing of the individual NOST and DIOnAS modules was completed, software integration was done and further integrations testing and operations testing was done.

Other articles in this newsletter describe the workings of and close coupling between the DIOnAS software and the NOST-created Data Migrator Utility (DMU) and the Package Splitter Utility (PSU) software now being used to move data from NDADS to DLT and to magnetic disk. The IMAGE article describes the NOST-created Package Generator Utility (PGU) software, an extension of DMU, being used by the IMAGE Project in its creation of Archive Information Packages. It also describes the evolved DIOnAS software and the NOST-created Extractor software to be used in the automated ingest of the IMAGE-provided AIPs at NSSDC.

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