The IB Computer Science case study 2019 deals with Computer Aided Dispatch (CAD). CAD systems are used by emergency telephone operators to help efficiently and quickly route firefighters, police, and ambulances to the scenes of emergencies. As the IB case study booklet highlights, CAD systems are safety critical systems and real time systems.
A New Computer Aided Dispatch System for Bangbai is the case study for May and November 2019 only. The Computer Science case study for November 2018 is Your Autonomous Taxi Awaits You
Below are examples of existing Computer Aided Dispatch (CAD) systems. They make useful background reading to help Computer Science students understand how CAD systems work and what features they offer. They can also help with the decision Rahul will need to make between regular and SaaS systems, and whether Bangbai can use a commercial off the shelf systems or will need a custom development.
TriTech Software Systems is a company that specialises in Computer Aided Dispatch (CAD) systems. They have a range of products that are well worth investigating as background research for the Computer Science case study. Their CAD+911 system can handle VoIP, text, and image data - which is stated as a requirement in the case study booklet (line 92).
Spillman are another company with a range of CAD systems. Their Spillman Flex system helps dispatch all three emergency services, while their Nova system is designed to provide CAD for police services only.
A variety of technologies - both existing and planned - are mentioned in the case study booklet. These resources cover these technologies, what they are, and how they work.
MDT technology is referenced in the case study booklet, with such systems being in use by many emergency workers. Although they might be regarded as legacy systems by some, they are still critical to effective dispatch systems. It isn't clear whether Bangbai uses these systems at the moment, but an understanding of MDT technology is still important.
How Firefighters Reduce Risk and Increase Preparedness Using Technology is an interview with a firefighter who explains the benefits of using mobile data terminals (MDT). Reading about the benefits from somebody on the frontline is a great way to understand the impacts of technology.
Load balancing algorithms are a key part of any Computer Aided Dispatch (CAD) system, and it is explicitly mentioned that Rahul is concerned about load balancing in light of Bangbai's rapid growth.
As a safety critical system, zero downtown is critical for the Bangbai CAD and EMIS systems. Failover and redundancy are keys ways of achieving these goals.
RAID is a technology for redundant data storage. This video clearly explains the different types of RAID and how they impact performance and reliability.
REST is a common protocol for data transfer over http. REST APIs are frequently used by systems on the Internet that need to expose functionality to other systems. For example, Flickr, Instragram, Facebook, and many other sites all have REST APIs to allow code to access data held within their systems. It is reasonable to assume that Bangbai might use a REST API as part of their new EMIS system to allow applications such as smart phone apps to send and receive data.
This video explains the basic concepts of REST, including sending and receiving data. It explains clearly how URLs are constructed and gives examples of REST APIs in use.
This section contains technologies which are not discussed explicitly in the case study booklet, but arose as a result of secondary research. They may be useful in helping Bangbai achieve its goals.
The Singapore Civil Defence Force (SCDF) may trial an AI system to help transcribe emergency calls automatically. The article briefly explains how the system might work, recognising words in English, Malay, and Hokkien. Perhaps if such systems are further developed, they could help Bangbai achieve its goal of increasing efficiency without increasing the number of operators in the ECC (line 80).
One of the drawbacks of the yearly case study is that there are no past paper questions to study for the Computer Science case study. However, the structure and requirements of the Paper 3 exam are clear. The exam always ends with a 12 mark essay question which requires students to combine a detailed understanding of technology with the issues raised in the case study. They should also make clear and explicit reference to research performed in class.
Below are some example 12-mark essay questions to help students practise. These are not official IB questions, as there are none.
Rahul aims to replace the CAD system with an EMIS system. Discuss some of the factors his team must consider when planning the changeover process. 
Rahul is considering purchasing a standard commercial off the shelf (COTS) EMIS system. With references to the requirements for a new EMIS in Bangbai, discuss this decision. 
With reference to the technologies involved, discuss how upgrading from a CAD to EMIS will affect the citizens of Bangbai.