Research-based personas and the resulting user/customer journeys simplify requirements and product development enormously, as they help to identify optimisation potential. This in turn helps to make well-founded decisions about product functions, interactions and navigation paths. to meet and to facilitate the prioritisation of functions.
There are often very different opinions within a team and company as to who the users or customers are and what their wishes, needs, questions and goals are. As a result, the term "User" or the "Users". However, these "users" are very malleable and can adapt perfectly to the opinions and assumptions of the person who is talking about the "user(s)". Alan Cooper, the "inventor" of personas, called this phenomenon "The elastic user".

Instead of being decided and prioritised from the user's perspective, which functions are planned or which features are implemented and when, decisions are made on the basis of opinions and assumptions or even from the perspective of technology.
The result is systems that are developed without users in mind and may be overloaded, offer no real added value, fail to stand up to competition or provide nothing new in terms of innovation.
One solution here is research-based personas. Research-based personas can serve as the starting point for journey maps, which in turn reveal the optimisation and innovation potential of products and services. This makes requirements and product development and the prioritisation of functions much easier and is based on well-founded decisions rather than opinions.
What are personas?
Personas are prototypical descriptions of representative users. They are created based on qualitative interviews and, if necessary, contextual observations. In short, personas are a way of summarising user research results. They are neither real people nor an "average" user, nor should they be based on stereotypes. They are User models.

Fig. 2: This is what a persona profile could look like: The persona has a name, goals, preferences, concerns and questions
But what does that even mean - "model"? George Box, a well-known statistician, once described this in his famous saying "All models are wrong, but some are useful" in a nutshell. Burnham and Anderson (2002) explained models as " (....) a simplification or approximation of reality (...) they therefore do not reflect the whole of reality." In short, models are used to represent complex things such as brain research, the universe or underground maps with a useful abstraction.
Personas are user models
Why do we attach so much importance to this? We are convinced that it is very important to make it clear that personas as Models because this means that we are aware at all times that they do not reflect reality 100%, but rather a Abstraction of this complex reality. They should be seen as tools for communicating research results and help to ensure a shared understanding of these results within the team or organisation.
This abstraction leads to the question: Why do we use models and not simply use reality?
The BVG underground map is an excellent example of a model. The map contains the most important information to get to the desired destination: clear names and colours for each line, the order of the stations on each line, the transfer stations between the lines, and so on. But the details that are less important to us as passengers - such as the depth of the individual tunnels, the exact distance between the stations - are ignored. A civil engineering company, for example, needs different models for this, because it wants to do something other than simply travelling from A to B. For us as passengers, such a level of detail in the plan would not be necessary, it could very probably even make it extremely difficult for us to read and make the plan incomprehensible to us.

Fig.3: A model of the BVG underground network with meaningful abstractions of reality
Even models of the universe do not explain how the universe works in "reality", but they make the concept tangible for non-astrophysicists and save us from having to pore over specialised journals to gain an understanding of the subject area.
Similarly, user research can be used to create descriptive models of the users. These models help to communicate the complexity of the interview data to the team in a more understandable way. Models show how things work in a consumable form that is accessible and easy to communicate. It is easier to communicate a few personas than to read all the ethnographic reports.
Personas inform the ACTUAL state of a user or customer journey
The research-based personas provide insights into questions, needs and concerns, as well as typical usage scenarios. From this information, it is possible to derive an actual state of the customer journey - with all its positive and negative experiences - the Pain Points. These pain points are exactly what is of great interest - because this is where the potential for optimisation and innovation lies.
What are journey maps?
A journey map is a representation of all interaction points (or: Touchpoints) between your users/customers (represented by the personas) and your product or service. Journey maps therefore represent the current user experience and are ideal for uncovering optimisation potential. The personas based on the interview data are used to determine the respective interaction points/touchpoints. The current state of the user experience is then "mapped" to these touchpoints. These can be both positive and negative experiences such as worries, fears, questions or concerns that were identified in interviews. This mapping reveals where the potential for optimisation lies: often precisely in the "gaps" in a positive user experience.
All of this is summarised in an overview so that it becomes clear exactly where the greatest need for optimisation exists.

Fig. 4: An example of what a user/customer journey map can look like
This description of the user experience with the product/service is then a valuable starting point for the following idea phase (Future scenarios/maps) as well as for the prioritisation of functions and further product development.
Conclusion:
Research-based personas and the resulting journey maps are excellent tools for subsequently developing well-founded ideas for exploiting optimisation potential. This in turn forms a solid basis for user-centred and prioritised requirement and product development, because with a cross-departmental understanding of your users and customers, you ensure that the entire team has a common understanding of the users and their goals and needs and make informed decisions about what should be implemented and when, thus reducing your cost risk in a new or redesign process.
Sources
- Alan Cooper , Robert Reimann , Dave Cronin, About face 3: the essentials of interaction design, John Wiley & Sons, Inc., New York, NY, 2007
- Burnham, K. P.; Anderson, D. R. (2002), Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach (2nd ed.), Springer-Verlag