CPSC 451 Customer Group 11

Automated Gas Station Requirements Specification

Version 3 (Final version for Assignment #1)

ASSUMPTION: The finished gas station is a franchise of a large petroleum company.

The requirements for this system are broken down into three categories:
Customer Interaction and Credit Checking: How the station interacts with its customers and their creditors;
Remote Operations: The remote controls needed to configure the station from the central office;
Accounting Procedures: The automatic report generation requirements.

Section 1: Customer Interaction and Credit Checking

We would like an automated system that is extremely user friendly and will allow for efficient transactions. Access to personal help would be available right at the pumps (preferrably through an intercom type system).

Step by step instructions would be visible on signs on or near the pumps. Text and graphics should be incorporated in this sign in a way that makes it easy to read and understand. This system is intended to run at maximum capacity 24 hours a day seven days a week, therefore efficiency and convenience is a top priority. However, it must meet all relevant CSA standards.

Beginning of Transaction:

A credit card would be inserted (not swiped) to start the transaction. Any major credit cards would be accepted including our own Petro 451 card and Interac debit cards. For the rest of this document we will take the phrase "credit card" to mean any of these things, and "creditor" to mean the bank or credit card company (or our credit office) whom we will be billing for the purchases.

Upon insertion of the credit card the machine would verify that the credit/debit card is valid by contacting the appropriate creditor and sending the information on the card. If the card is Interac, the user should be prompted to enter the PIN number as soon as the creditor has been contacted.

The creditor will respond in one of the following ways:

The following conditions must all be met in order for the sale to proceed:

If the card is not authorized then follow procedures laid out by each individual card company, including a mechanism for keeping stolen cards. Ensure that the machine can always resume operation after any errors other than an emergency.

Once credit has been authorized:

Prompt the customer for the type of gas they want (ie, Regular, Mid-grade, Premium or Diesel).

There should be an easy way for the customers to see the prices of all the different types of gas before they select one and start pumping.

Prompt the customer for the amount of gas they would like to purchase. For example, $5/$10/$20/Fill/Manual Control. The creditor will provide a maximum withdrawal amount, and the gas flow will automatically shut off (with a polite message displayed) if that amount is reached.

Once the selections are made, and if funds are available, the gas pump will be enabled and the customer can fill their tank.

While the gas is being pumped, the pump should display (in real time) the quantity pumped and the total accumulated charge so far. It should also display the type and price of the gas being pumped, and the tax rate.

After the nozzle has been returned to the holster the total purchase will be summed. A receipt will be printed for the customer as well as a hard copy stored in the machine, and an electronic record will be kept for the automatic accounting procedures outlined in Section 3.

The printed receipts would include:

The card and a receipt would be returned in a pleasant manner using society norms.

Section 2: Remote Controls

The following list of operations can be completed from head office via a remote link to each of the automated gas stations at any time. The methods used should be reliable enough that the changes and status checks for all the automated gas stations in the area could (but not necessarily will) be carried out by a batch process at the central office.

1) Sales

2) Safety

3) Maintenance

Underground storage tanks are filled as follows:

  1. The delivery person unlocks the tanks with a special access card and PIN at any pump. Also, the head office can remotely lock and unlock the tanks.
  2. After filling the tank, the deliverer enters the quantity unloaded. His/her special card is returned and the tank locks automatically.
  3. The station system records the information entered along with its own measurements of the quantities of gas delivered, and includes this information in the next report (see Section 3).

As a safety feature, the pumps should automatically shut off gas flow after either
a) The nozzle has been out of the holster too long, or
b) More gas has been pumped that is required to fill the largest common gas tanks.
Both these limits would be programmable and typically higher for diesel.

Section 3: Accounting Procedures

Each automated gas station will keep records of all events and report them electronically to the central office, at preset times by default but also upon demand. The preset times must be programmable to allow for busy locations to be set to make more frequent reports.

A backup of each report should be saved at the station for a week as a temporary safeguard.

If gas is being delivered or sold while the report is being generated, that transaction will appear on the next report.

The central office computer will handle printing the reports and generating monthly summaries and other sales statistics. For simplicity, assume that this central office computer system is already in operation.

The station reports sent to the office must contain the following information:

This report should be in a format both human- and computer-readable. ie, a text file with a simple and consistent format. The name of each field should either be printed in the file or provided on a reference sheet in the user manual.

This concludes our informal specification for the automated gas station control system.

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