Needs assessment is the first step in the iterative design loop. The goal here is to have a detailed record of the problem space you are going to be designing in.
The Problem Space
In this step of the design process, you need to define the problem space. The problem space is the system that encompasses and surrounds your defined solution. As you define the problem space you should be thinking about questions including, but not limited to:
What are we trying to achieve?
Why are we trying to achieve it?
Who does it affect?
What other systems will be affected by the designed solution?
What effects will the designed solution have on other systems?
In order to be as effective as possible defining the problem space you should:
Clearly outline the problem that is being solved, and
Identify the users in the problem space (including secondary and tertiary users).
Primary users directly interact with the designed solution
Secondary users indirectly use the designed solution
Tertiary users are affected by the designed solution
Requirements, Constraints, and Criteria
Requirements, constraints and criteria are a critical component of a needs assessment, and will be used by yourself and others involved in the project to guide design decisions throughout the project’s life. All three should be measurable.
Requirements
Requirements are design specifications that need to be met in order to consider the design complete. If a requirement is not met, the designed solution is incomplete.
e.g. The aircraft must have a flight time greater than or equal to 15 minutes without any payload
Constraints
Constraints are design specifications that need impose strict limits on the designed solution. If a constraint is ignored, the design solution is also incomplete.
e.g. - The sensor must not take longer than 2ms to provide a reading to after a request is made
Criteria / Objectives
If there is a specification that needs to be communicated but is not a requirement or a constraint it is likely to be a criterion. A criterion communicates important design goals that are impossible to capture in requirements and constraints.
e.g. - The ground station’s aircraft visualizations should be easy to understand
Developing the Needs Assessment
Throughout your development of the needs assessment, you should be careful to ensure that you are including all users in the problem space in the process. This could be directly asking them for requirements or performing interviews to understand the reasoning for their decisions and desires.
You should also take care to record as much information as possible as you develop the needs assessment. This includes your assumptions as you begin, research you do, and the requirements you develop.
When you have completed the needs assessment, be sure to summarize the problem so that it can be easily communicated to others as they become involved in the project.