T3: System Analysis v2
From SoftwarePractice.org
Contents |
System Overview
The main purpose of the IMS is to monitor road usage at different intersections over the city which are accident-prone.
The IMS will monitor and analyse the video & audio data in real time to identify and report accidents, speeding and red-light violations to the central Monitoring Point(CMP).
The recorded data (video and audio) relating to an accident will also be used to analyse and develop possible theories as to what went wrong and decide the probable cause/causes of the accident.
Below are the sub-sections that make up this section.
1.1 System Narrative
To improve the safety, minimise accidents and clamp down on bad driving at black spot intersections through out the state, the New South Wales (NSW) Road Traffic Authority (RTA) and the Roads Minister, Eric Roozendaal has commissioned to roll out next generation monitoring systems based on a trial monitoring system on the corner of Crown Street and Oxford Street in Sydney. The intersection has been a black spot for some years due to the difficulty of seeing other traffic and casual pedestrians and has been increasing year on year. In response to several residents in similar areas with problem intersections have approached their Member of Parliament (MP) in order to reduce the accidents taking place in such areas. One such case is the intersection of Windsor road/Seven Hills road/Old Northern Road where residents approached their local council in order to improve the safety of the intersection for pedestrians and road users.
From this there was a joint initiative with the Road Minister, Eric Roozendaal, the RTA and the local councils that have black spot intersections based on data that have been gathered from the last five years. The state government based on this commissioned a project worth one hundred million dollars based on the test run on an existing system found on the corner of Crown Street and Oxford Street in the city.
From initial requirements gathering from all the stakeholders mentioned above as well as the public input and residents around the area, the system requirement was to find out what was happening, cameras continuously recorded the traffic. The characteristic sounds of an accident triggered the system to preserve the last few seconds of recording. Periodically, the stored recordings were downloaded and analysed.
This project will build upon the trial and introduce new improvements and technologies while reducing costs for the next generation of highway monitoring. What will be delivered is an unobtrusive way to monitor traffic either at an intersection or on a stretch of road and monitor what happens. The system will recognise different types of vehicles and record the frequency of each type so that the pattern of road usage can be determined. The system will also record any unusual event, such as an accident, and send a message to a central point.
From the implementation of this system it will reduce the response time for emergency services to the area. It will also allow for in the future to allow emergency services to analyse the accident on their way to the incident so they are better prepared for what has occurred, thus reducing time to respond. It will also allow the RTA to improve services and building of better intersections and upgrading existing ones by studying the data that has been obtained. It will also allow the residence to have a peace of mind and users of those intersection that there is a twenty four hour, seven days a week monitoring system that will help in an event of any incidences and help to reduce the amount of accidents that happen.
1.2 Stakeholders
Here we have named all the stakeholders that have some vested interest in the project and we have also outlined whom they are, their interest towards this project, the benefits that this project will have to wards them, their power to promote or impede the project and a quality narrative to give an example.
| 'STAKEHOLDER | IDENTITY | CHARACTERISTICS | NATURE OF INTEREST | Benefits | PROMOTE | IMPEDE | USAGE NARRATIVE |
| RTA | Is the government body responsible for the roads, traffic, licensing, maintenance and up keep of the traffic and roads infrastructure as well as legislative duties | The RTA is expected to uphold all legislative duties that coincide with roads and traffic infrastructure in New South Wales and registration of vehicles. It issues fines for impeding laws that it is responsible to govern and also the welfare of the infrastructure. It is also responsible for licensing drivers that will use the roads. It is the central government body for roads and traffic in NSW |
| The IMS system will help the RTA manage roads around the city, making sure that traffic around the city doesn't slow down or come to a complete stop that inhibits the way the city runs. | 5 | 5 | Narrative 1: James at the RTA wants to analyse the intersection at the Oxford and Crown street, while he is analysing the intersection on the IMS Interface an incident occurs and it warns him of this incident on the IMS Interface, he wishes to access the build up to the incident to see how it occurred and what happened during and the of aftermath of the incident
Narrative 2: Troy, Jame's manager would like to see the the major incidents that occurred during the week so he can present a report and presentation to his Managers Narrative 3: Rachel notices that the IMS on the corner of Windsor and Seven Hills Road has gone down due to a warning that is displayed on the IMS interface. |
| Motorists | The people who use the roads using vehicles of different varieties. | Motorists are the users of the road. Characteristically they can be impatient as well as having a short fuse. As such they want the traffic to be as minimal as possible so they can get to the destination as quick as possible. So as long as the traffic is moving the motorists will be happier than not moving at all. |
| As the RTA will be able to manage the roads better then the traffic will be better so the motorists will have smooth runs around the city. | 1 | 1 | Narrative 1: Beryl is driving home from a late shift at work at 11:45 pm on a Saturday night. She is stopped by a red light at a monitored intersection. Beryl waits for the green light as proceeds to cross the intersection, however a truck driver who is running late for a delivery decides to run the red light going the other way and collides with Beryl’s car. The sound of the collision sets a flag in the monitoring system. This causes the system to save the last 15 seconds of audio and video footage and send a message to the central monitoring department. |
| Emergency Services | Services that use the road for different reasons. These include the Ambulance Service looking after sick or injured people, the police who uphold the countries laws, and the fire services that help to put out fires of different types in buildings or in the bush. | The emergency services are also users of the road. But for a different purpose. They help people who are in need of help in different emergencies. As such they want minimal traffic so that shorter routes to help people can be found so that they can help as fast as possible. |
| With traffic running smoother it means the Emergency services have quicker routes to get to the emergency situations that they help keep in check. | 4 | 2 | Narrative 1: The Sydney City Emergency Services is responding to a crash at the corner of Crown Street and Oxford Street in Sydney. The know that a Truck has run into the side of a small Toyota Camry and that the Driver of the car is trapped. Due to the IMS system that is in place they are able to get a video feed of the accident from the CMP and are able to plan their course of action before arriving on the scene and thus saving time on evaluating the situation. |
| Pedestrians | People who use the roads but not in vehicles. | Pedestrians are the main users of roads, even though people may not think of it as such. They use the roads for transport just as much as cars, put they are slower and more fragile as they aren't encased in a metal vehicle. as such characteristically pedestrians use the road and sometimes think that they have right of way and that all cars should stop. For Pedestrians to be safe then need motorists to be alert and not frustrated into making mistakes. |
| With traffic running smoother there will be less angry motorists trying to get through orange or red lights making the rods safer when pedestrians can cross the roads. | 1 | 1 | Narrative 1: Jim is walking to the parking structure where his car is parked. He stops at an intersection and notices that it is an intersection that is monitored intersection. When the pedestrian light said to he crossed the road. Unfortunately a driver was trying to speed through the intersection trying to beat the red light, and slammed on his breaks too late. Jim is then hit as the car is slowing down and injured. The accident triggers a flag at the monitoring section and there is evidence of the car hitting him at the intersection. |
| Developers | People who helped to create the IMS system. | Same as Motorists and tax payers. They also want to get contracts for developing products so that they can pay for living expenses. |
| Gives them a job to do so that they can support themselves and their families. | 2 | 2 | Narrative 1: Nathan is a programmer who has been contracted to work on the IMS system to be installed in intersections around the city. His specific job is to help program the system that is used at the interface at the central monitoring point. |
| Technical Support | People who help maintain and run the IMS system. | Same as Motorists and tax payers. They also want to get contracts for maintaining products so that they can pay for living expenses. |
| Gives them a job to do so that they can support themselves and their families. | 1 | 4 | Narrative 1: The RTA maintenance staff is responsible for maintaining the IMS in the case of a fault. In this situation, the IMS is able to send an alarm to the CMP that there is a fault in the system. With this function, technical support is able to be on site as quick as possible to fix the issue. |
| Government | The government is an institution that helps to keep a country running. | Characteristically Governments all over the world aren't necessarily the countries favorite people. The government though has what they think is the countries best interests in mind. They use the tax payers tax dollars to pay for services and utilities for the country. |
| With less traffic then the road users will be happier and criticize the government on how to do its job less meaning they have more time for more important issues. | 5 | 5 | Narrative 1: There is a growing number of accidents at a number of remote intersections. The minister of Transport orders a monitoring system to be put in place to find ways to reduce accidents. The IMS must be activated by the sound of a crash and 15 seconds of video and audio prior to the accident must be saved. A notification needs to be sent to a central monitoring system for an operator can assess the situation. |
| Construction Firms | The People responsible for building and installing the physical components of the IMS system. | Same as Motorists and tax payers. They also want to get contracts for building and installing products so that they can pay for living expenses. |
| Gives them jobs so that they can support themselves and their families. | 3 | 3 | Narrative 1: John is an electrician who works for a larger firm that has been contracted to build and install the IMS system in one intersection and if it proves to be a success then it will also build and install the IMS system on more intersections around the city. |
| Tax Payers | Everyone who works in the city/state. The taxes then supply the Government with financial support to fund projects like the IMS system. | Tax payers use the goods and services provided by the government that their tax dollars pay for. They also always want to pay less tax even when they use a lot of the goods and services that the tax can pay for. |
| Will be able to see their tax dollars at work to help traffic conditions. | 1 | 1 | Narrative 1: With growing numbers of accidents, Jim, a tax payer and also a pedestrian and a road user, wish to go home earlier. With the installation of the IMS, the traffic is able to be monitored closely so that traffic can be managed easier. |
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1.3 Contextual Factors of the System
Organisational Factors
The RTA is responsible for the upkeep and maintainability of the IMS system. It will house the central monitoring facility that will oversee the running and maintainence of the traffic light monitoring systems at intersections throughout the state. For now the system is tailored towards the needs of NSW and adhere to the laws that are governed in NSW. The RTA can also use the system for research on improving road use as well as enforcing the laws due to unsafe driving.
In all the RTA has a responsibility to uphold the legislation in NSW for road use, licensing users and the upkeep and maintainence of the roads infrastructure and also the assurance of quality and safety aspects of all of the above.
Technological Factors
The building of system will make use off shelf parts with a custom container to ensure tailored performance and requirements are met, such things as the audio visual equipment and data storage facilities. In doing so the custom software will enable to use these equipment but tailor their use and performance to the specifications as the main focus will be performance and scalability, this is something that can be met with current technologies already available.
Legal and Ethical Factors
One of the main issues in this will be privacy and use of the information obtained. But this can be governed by legislation similar to 24 hour speed cameras.
Business and Economic Factors
The factors concerned here is that this will not be a revenue generating initiative but more in order of reducing incidents and saving lives and therefore the benefits will be sought out in different means. But reducing accidents and fatalities on these black spots the saving towards the state in terms of resources such as emergency services being dispatched to these areas can be reduced and bringing those responsible if found guilty of irresponsible actions can be dealt with quickly.
1.4 Functional and Non-Functional Requirements
In this section we outline the quality narratives for each of the quality products below and from there we deduce how important these qualities are to the stakeholders that we have discussed above in section 1.4.
The table below indicates the priority of each quality component with respect to stakeholders. The following sections justifies the table.
The RTA regards each quality component as important. Motorists are more concerned that the fines they received are justified and that if they are involved in an accident, emergency response times are shortened. Also, security is important to them as they do not want video/audio of them leaked. Emergency Services want to respond to valid emergencies only and they want to be notified of a an accident promptly. Pedestrians have similar interests to the IMS as Emergency Responses - only they are lest concerned if Emergency responses receive false alarms and more concerned that if they are involved in an accident, help is on the way promptly. Also, security is important to them as they do not want video/audio of them leaked. Developers have similar priority to the RTA as the Specifications are agreed upon in a contract. Technical Support: The higher the performance, usability, reliability and maintainability the less support required. The Government want the reports to produce reliable data for statistical purposes and obviously does not want this information to be obtained or sabotaged. Construction Firms will be responsible for high performance hardware, future installations in other intersections and the maintenance of the system. Tax Payers want the money spent on the project to be efficient i.e. research is successful and can be used on a large scale.
It can be seen that the two most important quality attributes are reliability and performance.
| QUALITY | NARRATIVE |
| Security |
Narrative 1: Michael is the Quality Manager. One of Micheal's responsibilities is ensuring criminals can not hack into the database to edit records of accidents and red light offenses. |
| Performance |
Narrative 1: Hung is the consultant hired to reduce costs to the government. Hung's report has argued that the Intersection Monitoring System will increase emergency services response times, make fining traffic offenders more easy and gathering data for statistical purposes in a more economic and accurate way. |
| Scalability |
Narrative 1: Hank works for the RTA and he wants to make sure that once the system has been tested on the initial intersection that the system can be implemented around the city. Narrative 2: Frank is a Senior Operations Manager and will introduce the system to more RTA staff for usage as the IMS is rolled-out to more intersections. |
| Reliability |
Narrative 1: The criminal courts considers the RTA records valid evidence when drivers are being convicted for offenses. |
| Usability |
Narrative 1: Delfine is an RTA operator who will be learning how to use the system. Although an intelligent person, she got the job through her looks and is not necessarily technically competent. |
| Maintainability |
Narrative 1: Rodney works for the development company that helped to build the system. He wants to make sure that once the system is installed that it is easily maintained just in case something goes wrong. |
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There is an allocation of 10 points per stakeholder to use to indicate their areas of importance in the project.
| STAKEHOLDER | SECURITY | PERFORMANCE | SCALABILITY | RELIABILITY | USABILITY | MAINTAINABILITY |
| RTA | 1 | 1 | 4 | 4 | 0 | 0 |
| Motorists | 1 | 1 | 0 | 6 | 0 | 0 |
| Emergency Services | 0 | 5 | 0 | 5 | 0 | 0 |
| Pedestrians | 1 | 1 | 0 | 6 | 0 | 0 |
| Developers | 2 | 1 | 3 | 2 | 1 | 2 |
| Technical Support | 0 | 1 | 3 | 3 | 2 | 2 |
| Government | 0 | 1 | 3 | 4 | 0 | 1 |
| Construction Firms | 0 | 5 | 3 | 0 | 0 | 2 |
| Tax Payers | 0 | 1 | 4 | 4 | 0 | 0 |
1.5 System Quality Attributes
Based on the above weighed rating across different quality attributes, we infer that our 2 most important attributes are
1) Reliability
2) Scalability
1.5.1 Reliability
The reliability of the IMS System will be based upon well written documented and tested software and hardware. We shall reduce complexity by implementing simple components that shall be responsible for single tasks.
Redundant servers, databases and network shall ensure that we do not have a scenario where a single link going down effects the entire system.
A well monitored GUI based error diagnostics and monitoring system will alert the users in case any parts of the system goes down. The system shall in real time will send status alerts and will greatly aid the software maintenance team in getting the system back up and running in case something does go wrong.
1.5.2 Scalability
Initially the IMS will be implemented in all the black spot intersections across Sydney Metro, but ultimately it will get deployed over a large geographic area.
The IMS implementation architecture consists of
1. The Intersection Management Unit
2. The Master Station
3. The Error Diagnostics Server
4. The Database System
This structure lends to scalability as the servers can be scaled out horizontally to meet the load of additional intersection units.
Adding new intersections will be as simple as installing a black box and a router.
