Template:Use Case

Point Of Contact: A Human

Description

Give a short descriptive name for the use case to serve as a unique identifier.

AddInformation00

Goal

The goal briefly describes what the user intends to achieve with this use case.

The data provider would like a data set to be included in various online catalogs and by adding information those catalogs require, that becomes possible. Other steps are required, but this is necessary.

Summary

Give a summary of the use case to capture the essence of the use case (no longer than a page). It provides a quick overview and includes the goal and principal actor.

The data provider will look over the data set to get a general idea of the domain and range of the data set. They would then look over guide which will suggest which XML micro documents to provide and also which sets will be needed to support specific formats (e.g., what must they define to support EML).

Once the data provider knows what information to provide, they go about the task of writing it down in XML fragments and binding those to the data set's DAP attribute set. They will do this using the NcML-based Ancillary Information System. NcML is an XML notation which can be used to add new attributes or replace exiting ones using files that are external to the actual data set. NcML also provides a syntax for defining new variables for an existing data set, although we won't use that for this design. See AIS Using NcML for information on the NcML-based AIS system planned for the WCS interface to the Hyrax Data server.

Since many data sets consist of a collection of files where the content is constant in space but varies over time (or exhibits similar properties of variance with relation to other parameters), data providers might be faced with the task of providing the same information tens, hundreds or thousands of times over, hardly ideal. However, the NcML-based AIS system will provide two ways to address this issue:

1. The writer may use NcML to mark some information so that it is applied to a collection of files, typically all those in a certain directory tree; and/or
2. The writer may choose to aggregate the files to create a new logical data set where each files is an array slice or tile. Attributes are then defined for the new data set once and apply to all subsets derived from that new logical entity.

Actors

List actors, people or things outside the system that either acts on the system (primary actors) or is acted on by the system (secondary actors). Primary actors are ones that invoke the use case and benefit from the result. Identify sensors, models, portals and relevant data resources. Identify the primary actor and briefly describe role.

Preconditions

Here we state any assumptions about the state of the system that must be met for the trigger (below) to initiate the use case. Any assumptions about other systems can also be stated here, for example, weather conditions. List all preconditions.

Triggers

Here we describe in detail the event or events that brings about the execution of this use case. Triggers can be external, temporal, or internal. They can be single events or when a set of conditions are met, List all triggers and relationships.

Basic Flow

Often referred to as the primary scenario or course of events. In the basic flow we describe the flow that would be followed if the use case where to follow its main plot from start to end. Error states or alternate states that might be highlighted are not included here. This gives any browser of the document a quick view of how the system will work. Here the flow can be documented as a list, a conversation or as a story.(as much as required)

Alternate Flow

Here we give any alternate flows that might occur. May include flows that involve error conditions. Or flows that fall outside of the basic flow.

Post Conditions

Here we give any conditions that will be true of the state of the system after the use case has been completed.

Activity Diagram

Here a diagram is given to show the flow of events that surrounds the use case. It might be that text is a more useful way of describing the use case. However often a picture speaks a 1000 words.

Notes

There is always some piece of information that is required that has no other place to go. This is the place for that information.

Resources

In order to support the capabilities described in this Use Case, a set of resources must be available and/or configured. These resources include data and services, and the systems that offer them. This section will call out examples of these resources.

Other Resources

Resource	Owner	Description	Availability	Source System
(sensor name)	Organization that owns/ manages resource	Short description of the resource	How often the resource is available	Name of system which provides resource