# Requirements Analysis in Disruptive Engineering Solutions Using the Paradigm of Living Systems
## 1 Introduction  
Research on product requirements goes back more than 70 years [1]. Nowadays we can count a significant number of contributions in this area. For example, concerning requirements analysis, there are almost 160,000 papers indexed in Clarivate Analytics from over the last 10 years. This is a strong indicator of the importance of a good and comprehensive definition of product requirements to develop a competitive solution. Competitiveness strongly depends on fulfilling customers' and users' requirements and expectations, but this is mostly related to one projection of the problem; that is, the one dealing with the adoption of a product. There are also projections connected to other stakeholders, such as producers, strategic partners, shareholders, etc. [2]. This reveals a complicated and complex landscape the definition and analysis of requirements. Complicatedness occurs because of many players that are involved, as well as from the large number of angles from which the product must be analyzed [3]. For example, there are different types of requirements--some of them are related to functionalities, some others with usability, and some others are focused on quality performance, etc. [4]. Complexity is mainly generated by conflicts that occur between different requirements [5]. For example, there are negative correlations between low product costs and high-quality performance. When the product is designed with a lifecycle perspective in mind, engineers face a large set of target-functions [6,7]. Things become even more challenging when engineers have to design innovative products, with little to no discussion of the current products. In such cases, all categories of stakeholders have difficulties in articulating the proper set of requirements--especially the end-users [8, 9, 10]. In these situations, it is also very difficult, if not impossible, to prove that the set of requirements is formulated properly and comprehensively. This is the mainreason for which agile approaches for product development have gained interest in the last 10-15 years [11; 12; 13]. These approaches, such as agile/SCRUM [14], spiral [15], and lean [16], consider that developers and end-users (as well as other categories of stakeholders) must work together, in sessions of gradual iterations, to formulate and discover what they really want from the new product by combining creativity and background experience with foreground experience over the journey of iterative prototyping of the new product [17; 18; 19]. There are some premises necessary to make these approaches effective, too. One of the necessary conditions is to have sufficient time and budget to ensure a multi-faceted exploration of the innovation. Another condition is to have cooperative end-users, properly selected and representative in terms of critical mass. But concerning agile methodologies for requirements definition and analysis, one crucial condition is to relate with end-users that have background experience in the field. This means that agile methodologies can be effective if the new product addresses high-end consumers, because this category of consumers is capable of articulating requirements and expectations about future products with concern to their past and present experiences with former products in the same family, as well as with concern to the vision they can see for the new product. Nowadays, a special category of consumers is coming to the attention of producers. This category is that of non-consumers. Concerning this category, producers are interested in designing and launching so-called \"disruptive innovative products\" [20]. Disruptive products, which can be better coined disruptive product-service systems [21], or disruptive solutions, address special niches in the market that have the potential to transform non-consumers into low-end consumers. These market segments have very little to no experience with products from the family of products that the innovation intends to target.