Risk analysis and system requirements - Essay Example

 Risk analysis and system requirements Overview The overall goal of the project entails the design and development of an app for a smart phone/PDA. The application should allow the user to remotely control domestic services and/or appliances around the house. In this regard, my project precisely aims at coming up with an app for a PDA for controlling the actions of refrigerators/freezers while in the house or even miles away from the house; through a portable lightweight interface. Life has been made easier and enjoyable through technological inventions (Sommerville 2006). Most of the refrigerators are controlled manually, and they require the user to be next to them. However, this project strives to come up with an app for a PDA that will enhance the operation of refrigerators by their users. The PDA app to be developed will make it easier and convenient for individuals to use refrigerators and get the most out of them. The app will be used to regulate temperature in the fridge digitally. Temperature is an important parameter that in part determines the performance of refrigerators. Since the main purpose of the fridge is to preserve foodstuff, this app should provide foodstuff type tailored temperature regulation. The user will be able to manipulate the temperature of the fridge by being in a position to set a specific period when the fridge is going to remain cold or warm. This will allow the user to achieve tailored result depending on the food stuff to be preserved. This device will also be used to open and close the refrigerator doors digitally. Although most refrigerators have a circuit breaker to regulate turning on and off, this device will also have the capability of turning the freezer on and off so that the user can regulate it according to his/her needs. This app will also be able to analyze the performance of the refrigerator and give a summary on activities like; number of times the door was opened in a given timescale, amount of power it has consumed, the time it had the last circuit break and when its going to have the next, offer warnings incase the user is at risk like a warning when handling food/fridge compartments with wet hands, and offer notices when some parts are faulty i.e. doors, temperature components, electrical circulation, humidity. In this case, the device will be portable so that the user can still get these analyses even when out of the house through Wi-Fi technology. The device will be helpful to the old and the disabled. The app will allow for convenient refrigeration control. The device will rely on wireless technology. The device will be light, portable and ergonomic with simple navigation. It will rely on low power requirements (either batteries or electric current). System Requirements User Interfaces The app will be installed on Wi-Fi enabled PDAs allowing the user to manipulate the refrigerator from any Wi-Fi hotspot. Users will use either virtual keyboards or touch screen technology on their PDAs to manipulate their freezers. The PDA should provide the app link on the screen so that a single touch opens up the app’s page where the user can operate the appliance. The page should offer options to the user on how to proceed. User can therefore be able to input commands and check analyses. Hardware Interfaces The app will be installed on PDAs with Palm Operating System, Software Interfaces The PDA should run on any platform with a Java 6 compatible Runtime Environment. This Includes Palm Operating System, Windows, Mac OS, Linux and Sun Solaris. Communication Interfaces The PDA should have Bluetooth to enhance exchange of data and Wi-Fi Connectivity. In this regard, users will be able to connect to the internet when in Wi-Fi Hotspots and operate their Wi-Fi enabled appliances. Functional Requirements The functionality of the app will depend on a number or factors. First, the PDA will need to be Wi-Fi enabled so that it can connect to the internet in Wi-Fi hotspots. Secondly, the refrigerators will also need to be integrated with simulators to receive the commands from the PDA. In this case, the appliance will be Wi-Fi enabled. The commands from the app on a PDA will be transmitted through the web and received by the simulator on the appliance allowing for the execution of the command. This will require installation of digital thermostats that use relay or semiconductor device (triac) to act as a switch control for the HVACR units. The digital thermostat shall also have in built PID controller so that the thermostat can foresee how the system will react to its commands. Performance Requirements Continued performance of the app will rely on user environment. The user will be required to be in Wi-Fi hotspot with good internet connectivity speed. On the other hand, the appliance will need to be in a Wi-Fi hotspot with a reliable power source. The user will be required log in using user authorization password (with 8+ characters) in order to secure the usage of the app. Only users with authorization passwords will be able to access the user panel of the app on PDAs. Design Constraints Designing and developing real time software today proves to be a sophisticated juggling act (Chandrta 2004). Today’s systems employ more functionality than ever; elaborate GUIs, network connectivity and inter-processor communication. At the same time, the time constraint has to be met. Cost of production will also be a strong challenge because the project calls for great investment from key players. Others will include interface/protocol requirements, standards compliance, network communications, end user environment, availability of resources and interoperability requirements (Appleton 2004). Risk Analysis Since the app will depend on wireless connectivity, some risks inherent in wireless connectivity could be eminent. Wireless technology uses WAP/Bluetooth protocols for communication (Wiergers 2003). Each of this protocol has built in security to block break in by hackers. This could be problematic for apps that require user identification. In this regard, access control flows may arise allowing un-authorized access. This issue arises when we have unclear access policy and improper app design (inadequate input validation). Such risks can be avoided through accurate input validation and clear definition of the access policy (Ankolekar 2003). Buffer overflows could also arise causing the app to lose control of its execution. Again, input validation will be vital in handling this risk. Project Plan The project requires cooperation from three key players; a refrigerator manufacturer, Wi-Fi Service provider and me. The app will require windows 5 PDA (palm OS) and Web platforms. The IDE includes Sencha touch/www.sencha.com/products/touch (HTML 5 based mobile app development framework) and JavaScript language. The table below shows project activities and their relative time estimates. Estimated time (TE) = (O+4M+P)/6. Optimistic time=O, Pessimistic Time=P, Normal Time=M (Stellman & Green 2005) Time Estimates (in Months). ID Activity Predecessor Opt.(O) Normal(M) Pess.(P) Expected time (TE) 1 a. Project documentation (start) - 0.5 1 1.5 1 2 b. Identification of potential partners 1 1 2 3 2 3 c. Project analysis by partners 1 & 2 1 2 3 2 4 d. The Design process 3 3 4 5 4 5 e. 1st Testing 4 0.5 1 1.5 1 6 f. Corrections/Improvements 5 1 2 3 2 7 d. 2nd Testing 6 0.5 1 1.5 1 8 h. Launch (Finish) 7 7.5 13 18.5 13 The following is a representation of the activities on a Gantt chart and a Network Diagram. Gantt chart 1st Dec. 11’- 1st Jan. 12’-a 5th Jan.-5th March 12’-b 10th March-10th May 12’-c 15th May-15th Aug. 12’-d 20th Aug.-20th Sept. 12’-e 1st Oct.-Nov. 30th. 12’-f 1st -30th Dec. 12’-g 1st Jan. 13’-h The yellow bars represent the start and end of the project. The brown bars represent various activities and their predecessors. Activity b can only start when activity a is completed. Activity c relies on the completion of both activities a and b. Consequently, the previous activity forms the predecessor of the next activity. Currently, the project is at activity a. Network Diagram Identification of Potential Partners-b The Design Process-d Start-Plan/project Documentation-a 2nd Testing-g Project Analysis by Partners-c References Appleton, Brad 2004, A Software Design Specification Template. Retrieved on Dec. 20th, 2011 from http://www.bradapp.net Ankolekar, VL 2003, Application Development and Technology Tools: Vulnerabilities and Threat Management with Secure Programming Practices, a Defense in–depth approach. Bethesda, Maryland: SANS Institute Press. Chandrta, C 2004, Design Constraints of Real Time Applications. Retrieved on Dec. 20th 2011 from http://www.codeproject.com/KB/architecture/Real_Time_Applications.aspx Sommerville, Ian 2006, Software Engineering. Boston, Massachusetts: Addison-Wesley. Stellman, A and Green, F 2005, Applied Software Project Management. Cambridge, MA: O’Reilly Media. Wiergers, KE 2003, Software Requirements. Redmond: Microsoft Press. Read More