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Decision Support Systems - A Sample Application


Business and Technical Objectives of the Selector Program


The R&S Series selector program will have certain business and technical objectives.


The business objectives include:

  • To assist sales representatives and in-house personnel to select and price the correct compressor model and configuration based on an initial choice of Single Stage, Booster, or Economizer type of compressor and an R or S Series of compressor configuration.
  • To provide the user the ability to directly select a compressor configuration (R or S Series) and model number in rate mode or to allow the system to automatically recommend the model number in select mode.
  • To conform to normal Windows interface standards. These standards require that an information system:
  • Be easy to use, and learn with consistent menus and appropriate use of window type in terms of modality
  • Have colors that are consistently applied in a non-offensive fashion for feedback purposes
  • Use fonts of standard types and sizes
  • Be able to provide interactivity features that allow the user to concentrate on the work at hand
  • Employ standard keyboard operations such as accelerator keys, and left and right mouse actions as would be expected of normal Windows programs
  • To provide internal FES employees utility programs that:
  • Have the ability to manage all data bases
  • Permit the distribution of pricing and licensing files
  • Assist with the configuration of compressor components by running engineering calculations in a batch mode


The technical objectives include:

  • A Windows NT environment
  • At least 8 megabytes of RAM, 24 megabytes is preferable
  • 5 to 10 megabytes of hard disk space
  • A printer with standard Windows fonts installed, particularly MS San Serif
  • A VGA or SVGA monitor with at least 600x480 resolution
  • Interfacing with external calculation engines provided by Howden Corporation


Use Case Model


The following diagram titled "Use Cases Diagram" presents a logical view of the R&S Series Program in terms of functions and actors. The ellipses represent the major functions of the software and are called "Use Cases." The major functions are Select Product, Print Product Info, Manage Analyses, and Manage System Tables. The stick figures represent actors or external entities or agents that the system will interact with. The external entities are the Sales Rep, the External Engineering Engines (those provided by Howden), the Customer, the End User, and the Marketing Director or other FES employee.


Use Cases Diagram




Select Product Process



The sales representative selects an R or S Series compressor product with the R&S Series software system.


Business context

The sales representative inputs parameters that are important to the customer and end user into the system in order to size, select, and price the appropriate compressor product for the end user.


Important organizational details that must precede this process follow.

  • The sales representative must be a recognized agent of FES.
  • The sales representative must have a licensed version of the system.
  • The sales representative is an agent of a firm that is qualified to install the product.
  • The software must have been successfully installed on a PC based 486 (Pentium is preferred) with a minimum of 8 MB of RAM (24 preferred), 5 to 10 MB of disk storage, and an SVGA monitor. A printer is required for hard copy output.


Standard path

  1. The sales representative uses a data entry form to enter initial decision variables.
  2. The system validates the decision variables, and if they are correct, passes the initial decision variables to an external engineering engine by means of an input file.
  3. The system makes additional calculations using the data in output file generated by the external engine.
  4. The system displays the output variables in the output file, additional output calculations and parameters, and warning messages on the analysis worksheet.
  5. The sales representative then changes as many decision variables on the analysis worksheet as deemed appropriate.
  6. The sales representative presses a calculation button on the analysis worksheet in order to perform another series of calculations.
  7. The system passes the data to the external engine by means of input file.
  8. The system makes additional calculations and determines whether to display warning messages.
  9. The system populates the next column in the analysis worksheet with return variables from the output file, and additional calculations and warning messages.
  10. The sales representative repeats steps 5 through 9 until satisfied with the compressor model as it appears on the analysis worksheet.
  11. The sales representative indicates a selected compressor model by clicking the column header of the appropriate product in the analysis worksheet.



There are three alternative compressor designs:

  1. Single Stage
  2. Booster
  3. Economizer


There are two alternative series or configurations within each compressor as seen in the following table. These alternatives have important consequences in dealing with the external engineering engine.

Compressor Series Alternatives

Compressor Series

Input File

Output File Howden External Engine
R Series Xin Xout XRVPERF.EXE
S Series Win Wout WRVPERF.EXE


Sample Screen Shots Below

A typical work flow analysis diagram


Key Benefits

  • Identify operational areas where information is failing to effeciently flow throughout the organization
  • Determine specific operational areas where a change in information flow / use will result in operational improvement


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Last updated 06/18/03 09:59:19 PM