Informal diagrams created in general-purpose diagramming tools are widely used in software architecture because they are quick to produce and easy to share. However, the lack of constraints in such tools often yields inconsistent notations and ad-hoc conventions, which in turn invite misinterpretation when diagrams are read outside their original context. Dedicated modeling languages and environments can mitigate these issues but are frequently resisted due to steep learning curves and disruptive adoption costs. Building on the flexible modeling paradigm, this paper proposes an approach to the lightweight formalization of informal diagrams. Grounded in observed industrial challenges and prior work on flexible modeling, we derive a set of design principles and instantiate them in an approach realized as a Draw.io plugin. We propose an approach that addresses challenges from industrial settings by enabling practitioners to introduce structure incrementally into the informal diagrams they already create, thereby helping resolve notational inconsistency and clarify meaning. Moreover, we show how our approach satisfies the guiding flexible modeling principles by introducing these model-like benefits without compromising the accessibility and speed of informal diagramming as valued in practice. The contribution enhances clarity and consistency within familiar workflows and lays the groundwork for subsequent capabilities such as rapid dissemination of conventions, enterprise-level aggregation, and additional quality checks should organizations choose to adopt them. © 2026, Science and Technology Publications, Lda. All rights reserved.

Software-intensive systems are characterized by intricate interactions, distributed structures, and ongoing evolution posing notable challenges for traceability, change analysis, and decision support. Modeling and versioning practices are widely used to manage this complexity; however, in practice, they are often fragmented, limiting the value that organizations can derive from them. To address this challenge, we map modeling and versioning practices to the benefits they enable, providing a structured framework for practitioners to assess their current practices and identify opportunities for incremental improvement. Building on findings from our previous interview study with multiple companies, together with insights from the literature, we identify four levels of modeling formality, five levels of versioning sophistication, and four categories of benefits, summarized in two mapping tables. Our contributions include a practitioner-oriented roadmap that helps teams reflect on current modeling and versioning practices, anticipate achievable benefits, and identify incremental adjustments that can add value with minimal overhead. An initial validation with industry representatives confirms the practical relevance of the roadmap and highlights its potential to guide structured reflection and improvement of modeling and versioning practices.

Avionics are highly critical systems that require extensive testing governed by international safety standards. Cockpit Display Systems (CDS) are an essential component of modern aircraft cockpits and display information from the user application (UA) using various widgets. A significant step in the testing of avionics is to evaluate whether these CDS are displaying the correct information. A common industrial practice is to manually test the information on these CDS by taking the aircraft into different scenarios during the simulation. Such testing is required very frequently and at various changes in the avionics. Given the large number of scenarios to test, manual testing of such behavior is a laborious activity. In this paper, we propose a model-based strategy for automated testing of the information displayed on CDS. Our testing approach focuses on evaluating that the information from the user applications is being displayed correctly on the CDS. For this purpose, we develop a profile for capturing the details of different widgets of the display screens using models. The profile is based on the ARINC 661 standard for Cockpit Display Systems. The expected behavior of the CDS visible on the screens of the aircraft is captured using constraints written in Object Constraint Language. We apply our approach on an industrial case study of a Primary Flight Display (PFD) developed for an aircraft. Our results showed that the proposed approach is able to automatically identify faults in the simulation of PFD. Based on the results, it is concluded that the proposed approach is useful in finding display faults on avionics CDS.