**6. Conclusions**

The importance of the proposed system for managemen<sup>t</sup> control in SMEs is understood by showing how the analysis with Mamdani's fuzzy inference system (MFIS) is flexible and can be adapted to the information of each organization. It considers the context of SMEs, where all the data is not always available, and several evaluations are based on the perception of the CEOs.

The second major finding was that Mamdani's model was ideal for the evaluation as the qualitative variables for analysis were ideological and linguistic.

Evaluation using fuzzy IF-THEN rules enables adjusting the analysis to the needs and available data, so the number of rules can vary, allowing for different results. These characteristics of MFIS make it widely applicable in different scenarios or countries.

The boundary lever shows the highest level of weakness in SMEs and must be given more attention as it returned a negative degree of presence in the business model. It is necessary to implement training in managemen<sup>t</sup> control for businesspersons who run SMEs as this could increase company performance and keep them sustainable over time.

The belief, diagnostic, and interactive levers show mid-level results (of use) with a positive trend. This specifically means that in SMEs that employed the tools, in belief, tools such as the formal definition of mission, vision, and strategy. Diagnostics tools related to budget and inventory systems, whereas interactive obtains information from employees that most interact with clients to use the feedback for the future of the organization. There was no significant difference between financial and non-financial performance. Furthermore, medium-sized businesses employ more managemen<sup>t</sup> control tools than small-sized ones, which is expected.

One of the main restrictions of the study is the sample size, which consisted of only 86 SMEs, with more belonging to small companies rather than medium-sized entities. In addition, the complexity of defining rules must be taken into account, considering the number of variables and the importance of a good team of experts to define the fuzzy rules.

This implies that future research should focus on an economic sector that would allow us to specify the degree of use of the managemen<sup>t</sup> control tools by industry. Nevertheless, we consider the results to open a path of study and analysis to develop and apply fuzzy methodologies to the field of managemen<sup>t</sup> accounting.

**Author Contributions:** Conceptualization, Formal analysis, Investigation, Methodology, Project administration, Writing—original draft, Writing—review & editing, C.N.; Formal analysis, Investigation, Writing—original draft, Writing—review & editing, J.M.; Formal analysis, Methodology, Writing—original draft, Writing—review & editing, F.-J.A.-C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Conflicts of Interest:** The authors declare no conflict of interest.
