Prototyping

Prototyping demonstrates online dialog flows between screens without action diagrams, or generating code or databases. Prototyping verifies that the screens and flows are complete.
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Objectives
The following are the objectives of Prototyping:
  • Verify fields on particular screens
  • Identify missing screens and invalid dialog flows
  • Test flows between screens
  • Review screen appearance
Prerequisites
Before you use Prototyping, you must define your business system, screens, dialog flows, and commands.
Deliverables
Prototyping shows the customer screen design through the dialog flows and procedures. To prototype online dialog flows, the analyst builds the following items:
  1. Procedure steps to be prototyped (except for the action diagram)
  2. Dialog flows connecting the procedure steps
  3. Autoflows and the associated exit states for each dialog flow to prototype
  4. Function key assignments for each command that has an autoflow that is specified
  5. A screen for each procedure step
Downstream Effects
By using the Prototyping Tool before refining the action diagram for procedure steps, you can avoid costly changes later in the project.
Using the Prototyping Tool
The Prototyping Tool displays the screens in the same manner as in Screen Design Display. You cannot enter any variable data, interpret data, transfer data between screens, or simulate the look of data on the screen while in the Prototyping Tool. Function keys that are associated with the autoflows let you move from screen to screen based on dialog flows.
The cursor position does not change to indicate which fields are protected and which allow data entry. The edit pattern does display with each data field. Prototyping allows you to review the fundamental behavior of an online conversation without building detailed procedure logic.
While reviewing the screens, the customer can change screen definitions and the order in which screens are presented with an immediate review of the results. This ensures that the analyst and the customer agree on the screen changes.
Prototyping helps avoid changes later in the development process.
When prototyping is initialized, a keyboard function is loaded that captures all keyboard function keys including the F1 (HELP) key. Therefore, F1 does not work for HELP in the prototyping tool. You must select HELP from the tool bar.
Example
The following example shows how the procedure steps, dialog flows, function keys, and screens work together during Prototyping.
The procedure action diagram (PAD) shown in the following diagram identifies the exit states and the autoflow to the next logical screen. The EXIT STATE IS action sets the value of the special attribute Exit State. Exit States indicates what happens at the conclusion of a procedure. To support Prototyping, set Exit States to autoflow which initiates the dialog flow.
The Dialog Flow Diagram shown in the following diagram enables the transfer of control and data from one procedure step to another during system execution. A link indicates that the source procedure step passes control and data (optional) to the target procedure step. In this example, a link exists from Order Entry to Customer Maintenance and Part Maintenance. A transfer indicates that the source procedure step passes control and data (optional) to the target procedure step if appropriate conditions are met. In this example, a transfer exists from Order Entry to Order Maintenance and Customer List.
The following diagram shows the Order Entry screen, the starting point for a link or transfer:
The function keys identify which procedure step to activate for a selected function key. When demonstrating a business system, activate a screen in Prototyping. Then, use the function keys to move between screens as defined in the dialog flows and PAD. The following function key list identifies that F2 has been assigned to activate the CUSMAINT (Customer Maintenance) procedure step:
By pressing F2 from the Order Entry screen, you pass control to the Customer Maintenance screen, which is shown in the following diagram.
In the generated system, linking to the Customer Maintenance screen retains the original views that are defined for Order Entry and then adds input from Customer Maintenance.
The following functions work together during Prototyping:
  • Exit states from the PAD
  • Transfers and links in the DLG, which pass control and data between the procedure steps
  • Function keys and commands from Screen Design