Design and Implementation of SOS Smart Home Systems: Diagrams Project

This project presents the design and implementation of a smart home system for SOS Smart Home, utilizing various UML diagrams. The assignment begins with use case diagrams, starting with a basic representation of user interaction with smart home devices, and progresses to more detailed diagrams incorporating features like authentication, device status viewing, and integration with smartphone applications. The design team continuously improved these diagrams to include smart door sensors, device relationships, and a comprehensive view of all smart devices. Activity diagrams illustrate the system's operational flow, including server initialization, internet connectivity, and user login processes, along with the use of class diagrams to describe operations and constraints. Diagrams for subsystems like smart door sensors, heat and humidity detectors, and fire detectors are also provided, along with state machine diagrams showing device states and an entity-relationship diagram detailing database components. The project emphasizes object-oriented methods, with Java suggested as the programming language, highlighting classes such as Owner, Login, and selectAppliance. The diagrams collectively offer a comprehensive overview of the smart home system's design and functionality.

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SOS Smart Home
Name
Institution
Date

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Use Case Diagrams For the Smart Home.
Use Case Diagrams are referred to be behavioral diagrams by many system designers
worldwide. SOS needs to provide simple diagrams that help to describe a set of actions mostly
known as Use Cases. They can also show how a system should perform by its own and by
collaborating with other external actors. Different people may come up with different system
design case diagrams but the best is always utilized when implementing the system. Just so as to
be competitive in its processes of design and installation, SOS Smart Home assigned her
designers the same roles of designing Use Case diagrams that can be used as guidance in
implementing the design of their smart home systems.
Fig 1.0
The initial and most simple use case diagram was the one on fig 1.0. This use case simply
gives a visual representation of how the owner works on the various devices in his/her smart

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home. Any time they want to use an appliance, they have to provide their username and
password. There is a great need for access and identity management as it keeps away
unauthorized persons from accessing the appliances at the home. An outsider should not at any
time have the luxury of using the smart home devices just like they want. This will help the
owner keep his appliances safe from physical harm. This will bring down the costs of
maintenance. When someone provides a wrong pin, they will not be allowed to proceed with
using the appliances. From fig 1.0, Reading mode describes the process with which the owner
views the list of all appliances in his home. He then selects on one, for instance, the smart alarm.
He will be able to see all the times that have been configured for the alarm to ring. They can also
add more alarms or delete existing ones.
Fig 1.2

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The initial diagram in fig 1.0 does not show all the use cases clearly. The designers had to
design yet a new use case that was more detailed as it has been shown on figure 1.2. After the
home owner has turned on the devices at his home and has been authenticated to use the smart
home appliances, they will then view a list of all the devices and observe their statuses. All these
can be done using an android or IOS smart phone. The SOS smart home designers in the middle
of the design process realized that so as to be seen as very valuable to clients, they had to come
up with a complementary system that assists the home owners to control their homes just by
using a smart phone. There are many other technology companies that provide smart home
design and installation services. To be on top of these companies, SOS smart home had to
develop the app as fast as they could.
When the home owner is at home, and he forgot some food cooking in the kitchen, the food
may cook until it burns producing smoke. The smart smoke alarm will detect this and
immediately sound an alert alarm to the owner. The use case in fig 1.2 gives this impression
clearly.

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Fig 1.3
More improvements on the design of use case diagrams for the smart home were continuously
made. The above figure 1.3 adds a couple of more other use cases into the previous diagram. The
smart door sensor was not indicated in fig 1.2. The user now after viewing the list of devices and
their statuses, he or she will have to activate or turn on the smart door sensor. Once the sensor is
on, it will send a signal to the smart alarm anytime a visitor is on the door.

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Fig 1.4
The above fig 1.4 is yet another design improvement made by the design team. You can note
here that the designers realized a small problem they made in the earlier designs. All the use
cases they made had no direct relationships which are usually shown by “<<include>>” symbol.
It is now clear on fig 1.4 that you must turn on the devices then you login so that you can have
full access to the devices. All the step by step procedures are now clear.

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All the use case diagrams from fig 1.0 to 1.4 did not visualize all the smart devices that are
installable at the home. The designers addressed this issue by coming up with a final use case
diagram. This is the best diagram that they finally agreed to utilize during implementation. The
Smart smoke alarm, the smart detector of heat, smart door sensor, the fan, and the detector of
heat and humidity are seen in this final design. It is noted that all the devices are managed by just
one single user who is the owner of the home.

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Activity diagram
Fig 1.6
This is the initial design of the activity diagram. After the initial node, the server is initialized.
This is a crucial step for a majority the smart home appliances since they are connected to a

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central database. The server in this diagram represents the local MYSQL database. The databases
in the cloud are assumed to be live since they are always online. The GSM module is then
initialized to ensure that there is internet connectivity. The devices will search the internet for
any patch updates and system updates. They will also retrieve data from the local database
containing information of the current state of the home and then give an update to the user’s
smart phone. On receiving the current state of the home, the owner will acknowledge the
information and then take appropriate steps or just leave everything as they are if normal.
Through the internet connection, available at home from the Wi-Fi network, the owner is able to
receive updates wherever they are outside their home.

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Fig: 1.7

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The design team again had to do some improvements on the activity diagram that was used to
implement their Smart home systems previously. Fig 1.7 is an improved version that has
addressed problems found in the past activity diagram. Among the concerns addressed were: The
owner has to initialize the server and internet connection before logging in to the system. This
change in the flow of processes aids in the smooth operation of the system. A user cannot
logically login or be authenticated into a system whose database is not online. When the local
database and the internet is brought up firing good, the user will be able to login faster with no
complications. This activity diagram ensures that a user cannot access the smart home appliances
before he is first authenticated.
Class Diagram
Fire and Smoke monitoring Alarm System
Heat and Humidity sensor
Security and Safety
Remote control
Server
Intruders monitor
Fig 1.8

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CLASS DIAGRAM
LOGIN SYSTEM
OWNER +Name:string +Status:Boolean
+Name: String +Password: string +login()
+Password: String +Access () +logout(t)
+get_value( ) +AccessType() +set_values()
+set_value ( ) +select_appliance()
+login (t ) +update()
+display()
HMESECURITY SY
+systemon:boolean
+systemoff: boolean
+securityalarm()
+smokealarm()
+monitoring()
association
ALARM
+status:boolean
+alert_type:string
+detect()
+On_alarm()
Fig 1.9