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Question 1 (70 marks) EXAM

You are recommended as an engineer coming from H.T.T.C Bambili to a grocery supermarket in

order to computerize their inventory management. The items on shelves will be marked with Radio

Frequency Identification (RFID) tags and a set of RFID reader-devices will be installed for

the power induced by the magnetic field of the RFID reader. An RFID reader consists of an antenna,

transceiver and decoder, which sends periodic signals to inquire about any tag in vicinity. On

receiving any signal from a tag it passes on that information to the data processor.

You are tasked to develop a software system for inventory management. The envisioned system will

detect which items will soon be depleted from the shelves, as well as when shelves run out of stock

and notify the store management. The manager will be able to assign a store associate to replenish

the shelf, and the manager will be notified when the task is completed.

REPUBLIC OF CAMEROON

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Course Code: CSCT4111 _ Course Title: Information system languages and …

Session: _ January 2019_________ Hall: ______ Duration Allowed: 2 Hours

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Based on the initial ideas for the desired functions of the software system, the following requirements

are derived:

REQ1. The system shall continuously monitor the tagged items on the shelves. Every time an item

is removed, this event is recorded in the system database by recording the current item count from

the RFID reader.

The system should also be able to handle the cases when the customer takes an item, puts it in her

shopping cart, continues shopping, and then changes her mind, comes back and returns the item to

REQ4. The system shall notify the store manager when a “low-stock” or “out-of-stock” state is

detected, so the shelves will be replenished. The notification will be sent by electronic mail, and the

manager will be able to read it on his mobile phone.

REQ5. The store manager shall be able to assign a store associate with a task to replenish a particular

shelf with a specific product. The store associate shall be notified by electronic mail about the details

of the assigned task.

REQ6. While the store associate puts items on the shelf, the RFID system shall automatically detect

the newly restocked items by reading out their EPC. The system should support the option that

customers remove items at the same time while the store associate is replenishing this shelf.

REQ7. The store associate shall be able to explicitly inform the system when the replenishment task

peripheral RFID devices. Assume that the software running the RFID readers will be purchased

together with the hardware devices.

A2. The tag EPC is unique for a product category, which means that the system cannot distinguish

different items of the same product. Therefore, the database will store only the total count of a given

product type. No item-specific information will be stored.

A3. Assume that the RFID system works perfectly which, of course, is not true in reality. As of this

writing (2011) on an average 20% of the tags do not function properly. Accurate read rates on some

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items can be very low, because of physical limitations like reading through liquid or metals still exist

or interference by other wireless sources that can disrupt the tag transmissions.

A4. Assume that the item removal event is a clean break, which again, may not be true. For example,

if the user is vacillating between buying and not buying, the system may repeatedly count the item as

removed or added and lose track of correct count. Also, the user may return an item and take

another one of the same kind because she likes the latter more than the former. (A solution may be

periodically to scan all tags with the same EPC, and adjust incorrect counts in the database.)

customers currently in the store, interacting with the items. We assume that the great number of

events will

“clog” the computer network or the processors.

Do the following:

(a) Write all the

that can be derived from the requirements REQ1–REQ7.

For each use case, indicate the related requirements. Note that one use case may be related to several

requirements and vice versa, one requirement may be related to several use cases.

(b) Draw the use case diagram for the use cases described in item (a).

(c) Discuss additional requirements and use cases that could be added to this system.

Question 2 (30 marks) CA

Consider again the Grocery Inventory Management system described in

. Focus only on

the summary use cases that deal with depleted stock detection, related to the requirements