Abstract: A software management structure is disclosed. A software application package is made up of several linked replaceable units (RU). Each RU is serviceable without adversely effecting the other RUs. The RUs are linked together in a hierarchical fashion in a series of levels. In the preferred embodiment, five levels are used: Application Group level (AG), Loadable Code Group level (LCG), Primary Functional Group level (PFG), Secondary Functional Group level (SFG), and Operational Code Group level (OCG). The AG level defines a group of computer programs combined to perform a high level application tailor fit to meet the needs of the user. The LCG level defines individual programs each created to perform a general task. The PFG level refines the common programs defined in the LCG level to a more specific set of primary functions. The SFG level refines the primary functions defined in the PFG level to an even more specialized set of secondary functions tailored closely to fit a specific user's needs.

Abstract: A software management structure is disclosed. A software application package is made up of several linked replaceable units (RU). Each RU is serviceable without adversely effecting the other RUs. The RUs are linked together in a hierarchical fashion in a series of levels. In the preferred embodiment, five levels are used: Application Group level (AG), Loadable Code Group level (LCG), Primary Functional Group level (PFG), Secondary Functional Group level (SFG), and Operational Code Group level (OCG). The AG level defines a group of computer programs combined to perform a high level application tailor fit to meet the needs of the user. The LCG level defines individual programs each created to perform a general task. The PFG level refines the common programs defined in the LCG level to a more specific set of primary functions. The SFG level refines the primary functions defined in the PFG level to an even more specialized set of secondary functions tailored closely to fit a specific user's needs.

Abstract: A recovery mechanism restarts jobs following correction of a system failure and automatically marks the jobs for interruption at a logical boundary. The logical boundary is above logical file updating functions such that logical files are in a known state when jobs reach the boundary. When a system failure is detected which has not yet resulted in lost data, an image of working memory, including hardware status is saved on nonvolatile storage. After the failure has been resolved, the system is initially loaded with operating programs (IPL) and working memory is reloaded from the nonvolatile storage. All jobs which were reloaded are marked for interrupt at a machine instruction boundary, and processing is started. After all jobs have reached the boundary, or a predetermined time has elapsed, processing is stopped and the system is re-IPLed. There are few system index recoveries to be performed, since most jobs reached a point where logical files were synchronized with corresponding data.