**Stage 1:**

The first study tool was the CEST (capacity for engineering systems thinking) assessment questionnaire [39]. The capacity for engineering systems thinking characterizes the individual and can be evaluated and predicted.

The questionnaire was distributed to the first group in stage 1, before and after completing various graduate courses in systems engineering. It included 40 statement pairs, with items focusing on preferences, specifically likes and dislikes towards activities, jobs, professions, or other personality types. Respondents were asked to choose between the two statements according to their preference in each statement pair ( *A* marking preference for the first statement and *B* for the second).

Here are two example items from the questionnaire:

	- A. I think that every employee should gain interdisciplinary knowledge and general knowledge in several fields.
	- B. I think that every employee should become an expert in his/her field. Learning more fields may lead to sciolism (to know a little about many subjects).
	- A. I like to discuss the needs with the customer.
	- B. B. I prefer to leave the contact with the customer to marketing experts.

The participants of the second group of stage 1 were asked to complete the CEST assessment questionnaire [39] and also the MBTI (Myers-Briggs Type Indicator) personality type test [40]. Additionally, supervisor evaluations were conducted to assess respondents' systems thinking capabilities [41].

The MBTI test is a tool to evaluate personality types using a psychometric questionnaire. The goal of the test is to help people identify their dominant preferences, tendencies, and personality traits. The questionnaire is based on the premise that people have four psychological functions through which they experience the world: Natural energy orientation, Way of perceiving or understanding and taking in information, Way of forming judgments and making choices and decisions, Action orientation towards the outside world (Lifestyle).

The result of this questionnaire is one of the 16 character archetypes, as shown in Figure 1.

The current study examined the connection between self-reported dominant personality traits (according to the MBTI research tool) and respondents' systems thinking capacity.

We examined a different kind of reliability and validity of the CEST (capacity for engineering systems thinking) assessment questionnaire. Two types of reliability were calculated: inter-judges reliability and alpha coefficient reliability. Four types of validity are presented: content validity, concurrent validity, contrasted group validity, and constructed validity.
