Oxford International Primary Computing Student Book PDF

## 5.2 Understand requirements ### In This Lesson - How to make the right technology choices by understanding requirements - How to prioritize requirements to make choices easier. ### Why is it important to understand requirements? Requirements are the things that technology needs to be able to do...

## 5.2 Understand requirements ### In This Lesson - How to make the right technology choices by understanding requirements - How to prioritize requirements to make choices easier. ### Why is it important to understand requirements? Requirements are the things that technology needs to be able to do, in order to help you achieve your project goals. In any project, it is important to understand as much as possible about your requirements before you start work. A project is strongly influenced by the early decisions you make, for example, about what software or hardware to use. The graph shows how difficult and expensive it can be if you do not plan and think very carefully about your needs early on in a project. It shows that as the project goes on, making changes to the product can become more and more expensive. If you have not thought carefully about your project needs, you might find there are requirements that your chosen technologies can't meet. It may be difficult and expensive to introduce new technologies. You might even have to redo some of the work. **Difficulty and cost of making changes to a product or service** | | | | | | |--------------------|--------------------|-------------------|--------------------|-------------------| | When deciding | When delivering | When testing the | When launching | After launching | | requirements | the project | product | the product | the product | | | | | | | ### How can you make the best choices? There are lots of different types of hardware and software to choose from. So it's important to have an organized way of making decisions. Here is a set of steps to help you: 1. Understand the things you are trying to achieve - your requirements. 2. Decide on what is most important. This is called prioritising. 3. Research your choices and how they match your requirements and priorities. This is called an options analysis. 4. Make your decisions based on your analysis. ### Creating a list of requirements These are the most important features of requirements for a technology project: - Use simple statements that are easy to understand, even by people who are not technology experts. - Include the role of the person or team. - Say what the person or team needs to achieve. You can start collecting requirements by listing the roles that you and your team need to perform in the project. When you have identified the roles, write down the requirements that each of these roles has. You can write your requirements in a table. In this project, the team roles are video editor, artwork designer, and camera operator. You will create your list of requirements in the activity at the end of the lesson. ### Functional requirements This table shows some roles and requirements for a video project like the one in this unit. The table also shows the priority of each requirement. You will learn about prioritising requirements later in this lesson. | Role | Requirement | Priority | |-------------------|---------------------------------------------------------------------------------------|---------------| | Camera operator | I want to be able to record high-definition video. | Must have | | Camera operator | I want to be able to check my recordings without downloading them from the camera | Should have | | Video editor | I want to be able to import video clips from a file-sharing service. | Should have | | Video editor | I want to be able to edit clips together to make a film. | Must have | | Video editor | I want to be able to add music to my video. | Should have | | Artwork designer | I want to be able to create charts. | Should have | | Artwork designer | I want to be able to combine text and images. | Must have | The requirements in this table are called functional requirements because they describe what technology must do to help the project. ### Non-functional requirements Most projects also have non-functional requirements. Non-functional requirements describe how a piece of software and hardware must work. You can write non-functional requirements as a simple statement. Here are some examples: - The software must process videos quickly, so that the editor can work with them. - The app must start up in less than 10 seconds. - A file-sharing service must be password-protected so that the files are not lost or stolen. - Hardware or software must cost less than $50. - Software or hardware must work with other products and services being used in the project. Non-functional requirements often have values that can be measured, for example, a time limit or an amount of money. These are known as **metrics**. Metrics can be helpful when comparing technology options. ### Prioritising requirements Projects often have many requirements. Often you can't meet all the requirements. This can make it difficult to choose a technology or service to help you deliver your project. Prioritising requirements can make it easier to decide. When you have put the requirements in order of priority, you can focus on meeting the most important ones first. Prioritise requirements by using three categories: 1. Must haves: things your technology or service must be able to do. If you can't do these things, your project will fail. 2. Should haves: things you should have but don't absolutely need, usually because there are other ways of meeting the requirement. 3. Could haves: things that would be good to have, but you can do without. ### Activity Download the requirements template. Review the project brief from the last lesson. Use the template to choose six functional requirements for the software, three needed by the video. editor and three needed by the artwork designer. Remember to think about all aspects of your project. Review the project brief again to make sure. Next, choose three functional requirements for the hardware, needed by the camera operator. Now prioritise your requirements by giving each one a 'Must have' or 'Should have' priority. Write an M or S next to each of the requirements. Work on your own or as a team. Keep your work safe. You will need it in the next lesson. ### Extra Challenge If you have time, write down some non-functional requirements for the software and hardware in your project. Think about: - The cost and availability of software and hardware. - How easy it should be to use - The compatibility of hardware and software. Ask yourself: - Can I find the device or software app in school or at home? - How much time do I have to learn how to use new equipment and software? - What apps and equipment need to work together in this project? ### Test 1. What does the word 'requirement' mean in a technology project? 2. Why is it important to prioritise requirements in a project? 3. Put these priorities in the right order: should have, could have, must have. Write a short paragraph describing the difference between these priorities. 4. Describe the difference between a functional and non-functional requirement.