The primary measure of a system
is the degree to which it meets the purpose for which it was
intended.
Requirements Engineering (RE) is the process of discovering the purpose
by identifying
stakeholders and their needs, and documenting them in
a form for analysis, communication and
implementation.
The following are the form, fit, and function requirements elicited for
our automated
inventory tracking system. Please refer to Figure 1 in the
Introduction for the Concept Diagram.
The system requirements for the
automated inventory tracking system have been broken into two
categories for simplicity: behavior and
structure. Behavior describes how the
system should function and
interact with the environment and actors, in
order to complete the intended task.
Structure describes the
form and fit portion of the equation and
determines how the system will complement our warehouse.
1.0 Behavior
1.1 Tags shall be capable of wireless,
short-range (one mile or less) radio-frequency
communications with the following:
a.
RF
Transceivers mounted in a warehouse
b. Manual tag programmers
1.2 Tags shall be capable of being programmed
with the following information:
a.
Unique
I.D. number
b. Type of material
c.
Quantity
d. Destination
e.
Time/Date
Shipped/Received
1.3 Tags shall have low power consumption, battery must operate tag for a minimum of one
year.
1.4 Tags shall transmit an alarm signal when
the battery power level is low. The tag
shall be
capable of low power operation for a minimum of
seven (7) days to allow ample time for
suspect tags to be identified, and batteries
changed.
1.5 Tags shall utilize non-volatile memory to
store data listed in 1.2, and be re-programmable a
minimum of 1000 times.
1.6 RF transceivers shall be capable of
receiving an RF signal containing tag data, convert the
signal to standard TCP/IP protocol for
communications over an Ethernet/Internet network.
1.7 RF transceivers shall be capable of
receiving TCP/IP messages from the local logistics
processor (LogProc),
converting the messages to an RF signal, and transmitting the RF signal
with sufficient signal strength to be
received by a tag that is located within one mile of the RF
transceiver.
1.8 The Logistics processor shall perform the
following functions:
a.
Communicate
over TCP/IP with the logistics database and RF Transceivers.
b. Have sufficient memory to store all tag
data for a single warehouse.
c.
Run
embedded tracking software that is updateable
d. Communicate with a GUI over RS-232 or
other standard peer-to-peer protocol.
e.
Communicate
with a manual tag programmer to allow downloading of tag data into the
logistics processor’s resident memory.
1.9
The
global tracking system software must provide functions and features that are
useful for
tracking and analyzing
warehouse/inventory operations.
1.10
The
logistics database shall be capable of storing current and historical tag data
that can be
accessed using the software in 1.9.
1.11
When
queried, the logistics database shall determine if there is a need for current
tag data
and shall retrieve the necessary data from
the respective logistics processors if the most
current data is not already stored in the
database.
1.12
Tags
shall operate within a temperature range of 0 to 90 degrees Celsius at a
maximum
95% relative humidity.
Tag operation shall be un-affected by typical airborne dust and dirt.
2.0 Structure
2.1 The system structure at the warehouse
level shall consist of the following interconnected
subsystems:
a.
Tag
b. Manual Tag Programmer
c.
RF
Transceivers
d. Logistics processor
e.
Cabling
between RF transceivers and logistics processor
2.2 The system structure at the global level
shall consist of the following components:
a.
Logistics
Database
b.
The
global tracking system software
c.
Wide-area-network
using TCP/IP protocol
2.3 Tags shall include a weatherproof
enclosure with a rating that meets or exceeds NEMA-3R.
2.4 Tag shall be a microcontroller-based
device that includes the following:
a.
Programmable,
non-volatile memory such as EEPROM or similar technology
b. Input/output ports with digital-to-analog
and analog-to-digital converters and other
necessary components to provide tag with wireless,
radio frequency communication
capability
c.
Long-life,
dry-cell battery
2.5 Weight of Tag component shall not exceed
5 oz.
2.6 Tag dimensions shall not exceed 3”x3”x1”
2.7 Transceiver dimensions shall not exceed
8”x8”x4”
2.8 RF transceivers shall include an Ethernet
port to provide a network interface connection
2.9 RF transceivers shall have integral
transformers, that are powered from a standard 120 VAC
source.
2.10 A warehouse shall contain no less than
one RF transceiver mounted on each wall to provide
adequate sensing of all tags within the
warehouse.
2.11 System shall have a GUI interface that is
compatible with the logistics processor.
2.12 The system must contain a long-range
communication medium such as an internet connection
or a satellite link to interconnect the
local logistics processors at each warehouse with the
global logistics database.
2.13 Tags shall store information in
non-volatile memory
2.14 The global tracking system software must
be capable of running in a network environment,
providing access to many users simultaneously on a
wide-area-network.
2.15 The logistics processor and its
peripheral devices must include the following:
a.
Rugged,
industrial-type processing unit
b.
Ethernet
I/O card
c.
RS-232
communications port for connection to a GUI
d.
Infra-red
communications port for wireless, I/O communications with the manual tag
programmer