An alpha field trial is an engineering field trial, not a customer or fieldsupport field trial, which includes all elements of the system. It usually is performed prior to software completion, but after the high priority and risk use cases are implemented. Its purpose is to test the product to uncover issues relatively early in the development cycle.
In its best form, alpha field trial is implemented by providing company personnel with product and user instructions. A weekly meeting is held to discuss any questions they have. This provides not only defect detection, but also a usability test of the product and its user documentation.
A beta field trial is a customer (or a field support department) trial conducted in a customer domain. This is performed after all software development is completed. The trial is extended with additional releases if failures should occur. A beta field trial is complete when the customer (or field support department) signs for acceptance of the product.
Maintenance covers the software product support from initial production release to the end of the product lifecycle. The SRD and SAS artifacts from the analysis and design process phases are critical to the cost and quality of maintenance modifications made to the software during this period. They are documents that a maintenance programmer can rely on being accurate and up to date at all times. The same software development phases used in the initial development apply to the maintenance activity.