Barrows and Tamblyn [9] described PBL as an approach in which a problem initiates and organises learning. Its emphasis on active inquiry, knowledge construction, and reflection is compatible with constructivist accounts of learning [25], [26]. Reviews of PBL identify potential benefits for flexible knowledge, problem solving, self-directed learning, and collaboration, while also stressing the importance of facilitation and task design [10], [27]. Walker and Leary’s meta-analysis further showed that PBL effects vary by problem type, implementation, discipline, and assessment level rather than being uniformly positive [28].

The operational sequence adopted in the module—problem orientation, learner organisation, guided investigation, presentation of a proposed solution, and evaluation—is adapted from commonly used PBL teaching phases [29]. Importantly, all five phases are represented within each jobsheet; the five jobsheets are not intended to represent one phase each. The problem scenario introduces the technical fault, group roles organise inquiry, FPWIN Pro 7 supports investigation and simulation, learner documentation supports presentation, and trainer-kit execution enables evaluation. This guided structure differentiates the module from an unguided discovery task and is consistent with problem-solving designs that combine authentic problems with explicit scaffolding [30].

The procedure followed three linked stages. Define established the instructional problem, learner characteristics, task requirements, concepts, and objectives. Design translated these requirements into the module structure, jobsheet sequence, PBL scenarios, safety guidance, and visual format. Develop comprised expert appraisal, revision, and a small-scale practicality trial. This sequence is reported to make the design decisions and the boundary between product development and product evaluation explicit.

3.2.1 Define Stage

Front-end analysis indicated that the Pick and Place Trainer Kit in the school laboratory did not have an accompanying written practicum guide and that instruction relied mainly on oral explanation. Learner analysis involved the eleven Grade XI Industrial Automation Engineering students enrolled in the course; they had introductory knowledge of electro-pneumatic components but limited or no prior experience with FPWIN Pro 7. Task and concept analyses organised the Electro-Pneumatic and Hydraulic Control Systems content into five progressively sequenced competency clusters, one for each jobsheet. Learning objectives used observable verbs at the Apply and Analyse levels of the revised taxonomy [36].

3 .2. 2 Design Stage

An A4 print format was selected for laboratory use. Each jobsheet contained: (1) a title and learning objectives, (2) time allocation, (3) equipment and materials, (4) concise technical background, (5) occupational health and safety (K3) guidance, (6) a PBL-oriented problem scenario, (7) guided work procedures with FPWIN Pro 7 screenshots, (8) observation and data-recording fields, and (9) post-practicum evaluation tasks. The visual design drew on characteristics of self-instructional and user-oriented modules [37]. Table 1 summarises the five jobsheets, their problem scenarios, and their intended learning outcomes.

3 .2. 3 Develop Stage

The development stage comprised two sequential sub-phases: expert appraisal (validity testing) followed by developmental testing (practicality testing).

Expert appraisal: The draft module was reviewed by two validators: one subject-matter expert in electrical engineering and PLC instruction and one instructional-media expert in vocational instructional design. Each validator completed a five-point appraisal form (1 = Very Poor to 5 = Very Good) for the domain relevant to their expertise and provided written comments. Because only one validator assessed each domain, the percentages are descriptive expert-appraisal results rather than estimates of inter-rater agreement.

Developmental testing: After expert-informed revision, one vocational teacher and ten Grade XI Industrial Automation students used the module during a two-session small-scale practicum trial. Students first developed and checked their programmes in FPWIN Pro 7 and then executed the verified sequences on the physical Pick and Place Trainer Kit. The teacher and students completed post-use practicality questionnaires immediately after the trial. Students also completed a pre-use expectation questionnaire; those scores were analysed separately and were not included in the post-use practicality mean.

The study was conducted at SMK Pembangunan Teknologi Robotik UNP, Padang, West Sumatra, Indonesia, a vocational school established under the auspices of the Universitas Negeri Padang, specializing in robotics and industrial automation. The practicum laboratory houses six Pick and Place Trainer Kits, each equipped with a Panasonic FP0 5.0K PLC unit and a workstation computer running FPWIN Pro 7. All eleven Grade XI Teknik Otomasi Industri (TOI) students enrolled in the Electro-Pneumatic Control Systems course participated. One teacher holding a master’s degree in Electrical Engineering Education and responsible for the automation practicum also participated.

Validity Instrument: Two expert validation sheets were developed, each operationalizing Nieveen’s [20] quality criteria. The content validity sheet (28 items) assessed curriculum alignment, the conceptual accuracy of PLC and electro-pneumatic content, the appropriateness of K3 procedures, and the quality of PBL scenario integration. The media validity sheet (24 items) assessed layout aesthetics, typographic legibility, image proportion, visual hierarchy, and language clarity.

Practicality Instrument: The practicality questionnaire (20 items for students; 22 items for teachers) measured ease of module use, instructional clarity, time efficiency, learner engagement, and alignment with the trainer kit hardware. Both instruments were validated for content by two independent reviewers and pilot-tested for internal consistency; Cronbach’s alpha values exceeded 0.80 for all scales, confirming adequate reliability.

Data Analysis: Validity and practicality scores were computed as a percentage of the maximum possible score using the formula (1) recommended by Riduwan [38]:

The five-tier interpretive scale used was: 81–100% = Very Valid/Very Practical; 61–80% = Valid/Practical; 41–60% = Moderately Valid/Practical; 21–40% = Less Valid/Practical; 0–20% = Not Valid/Not Practical. A minimum threshold of 61% (“Valid” and “Practical”) was set as the acceptance criterion, consistent with established practice in Indonesian R&D educational studies [32], [33].

As shown in Table 2, the content appraisal score was 89.58% and the media appraisal score was 93.75%; their arithmetic mean was 91.67%. Under the study’s predefined categories, all three values were classified as Very Valid. The content expert judged the PLC, electro-pneumatic, curriculum, K3, and PBL components positively, while the media expert rated layout, typography, image use, and visual organisation positively. Because each domain was assessed by one expert, these results should be read as domain-specific formative judgements rather than evidence of inter-rater reliability.

The subject-matter expert’s written comments focused on two areas requiring revision: (a) several FPWIN Pro 7 screenshots were too small to distinguish individual ladder rungs and required enlargement, and (b) the K3 section of each jobsheet needed more precise specification of the emergency stop button (X0) location and its role in the control circuit. The media expert recommended separating large screenshot figures from surrounding instructional text using explicit figure captions and adjusting the observation table columns to accommodate separate recording of pneumatic actuator stroke direction (extend/retract) and gripper state (open/closed). All recommended revisions were implemented prior to the practicality trial.

The teacher’s post-use practicality score was 93.8%, and the mean student post-use score was 95.0% (SD = 2.85). The participant-weighted post-use mean was therefore 94.9%, classified as Very Practical. The student pre-use expectation mean was 92.0% (SD = 3.12) and is shown only as contextual information; it was not included in the overall post-use practicality score. Although the post-use mean was numerically higher than the pre-use mean, the study was not designed or powered to test whether that difference was statistically or theoretically meaningful [39].

In the open-ended feedback, the teacher reported that the module reduced the amount of repeated verbal explanation required during the session. Students most frequently identified the step-by-step FPWIN Pro 7 screenshots and the opening problem scenarios as useful features. The most common requested revision was the addition of colour-coded wiring diagrams for pneumatic-solenoid connections. These comments informed the interpretation of usability but were not analysed as evidence of learning gains.

The participant-weighted post-use practicality mean was 94.9%. Harjianto and Zamtinah [15] reported a 77.01% student response for a different PBL-based jobsheet, while Haryudo et al. [7] evaluated trainer-kit use within project-based learning. These studies provide relevant context, but direct score comparisons are limited by differences in instruments, samples, learning models, and implementation. The present result shows favourable perceived usability in one local trial; it does not establish improved motivation, competence, or learning relative to conventional instruction.

Software-first simulation: The module required learners to check ladder logic in FPWIN Pro 7 before executing it on the physical trainer. This sequencing was intended to separate programme debugging from hardware operation and to provide a lower-risk opportunity for revision. Comparable PLC training-kit and module work supports the pedagogical value of linking simulation, guidance, and equipment practice [3]. However, this study did not systematically record equipment incidents, cognitive load, comprehension, or retention; those outcomes should not be inferred from practicality ratings alone [19], [42].

PBL problem orientation: Participants’ comments indicated that the opening scenarios helped them understand the purpose of the programming task. This observation is compatible with PBL accounts in which an authentic problem organises inquiry [10], [29] and with engineering-education arguments for realistic problem-solving experiences [43]. Nevertheless, engagement was not measured with a validated scale, group-discussion frequency was not systematically coded, and the result should be interpreted as qualitative formative feedback.

Self-contained structure: Concise technical explanations, equipment lists, annotated diagrams, and K3 reminders were intended to reduce unnecessary searching during practicum work. The favourable usability comments are consistent with user-oriented module characteristics described by Sukiman [6] and Daryanto [37]. The study did not, however, directly measure learner independence or standardisation of delivery, so these remain design intentions for future observation-based testing.

The student mean increased descriptively from 92.0% before use to 95.0% after use. Because the questionnaires represented expectation and post-use practicality rather than a validated repeated measure of the same construct, the difference should not be interpreted as an effect of the module. The result is best used to refine future evaluation. Subsequent trials should examine how much guidance learners require, because PBL is most defensible when authentic inquiry is accompanied by appropriate scaffolding rather than minimal guidance [40], [44].

Across the selected studies, development products were generally judged valid and practical within their respective settings, but the numerical results are not interchangeable. Differences may reflect instrument design, validator composition, participant characteristics, infrastructure, and implementation conditions. The present teacher and student ratings were both high, yet the single-site sample is too small to separate module quality from contextual support or response tendencies. Broader trials using common outcome definitions are needed before generalisability can be assessed.

The five-jobsheet sequence progresses from basic I/O logic to timers, counters, memory functions, and integrated Pick and Place control. This progression is relevant to the increasingly complex skills expected in technology-intensive vocational work [2] and uses an IEC 61131-3-compliant programming environment [24]. The scenarios also expose learners to representative faults such as missed counts and sequencing errors. Whether this design improves workplace troubleshooting competence remains an empirical question for performance-based and longitudinal research.

Several limitations qualify the findings. First, the study stopped at Develop and did not implement the Disseminate stage. Second, the practicality trial involved one teacher and ten students from one school, while each validity domain was assessed by one expert; the results cannot be generalised statistically and do not provide inter-rater evidence. Third, the questionnaire evidence was self-reported, internal-consistency estimates were not established for the small trial, and the pre-use and post-use forms were not demonstrated to measure an identical construct. Fourth, no control group, pre-/post-test of competence, observation protocol, or performance-based assessment was used. The study therefore supports preliminary validity and perceived practicality only, not effectiveness, causal impact, or industry readiness.

Future research should: (1) conduct multi-site trials with larger and more diverse cohorts; (2) use multiple validators per domain and report agreement or reliability evidence; (3) compare the module with an appropriate alternative using knowledge, programming, troubleshooting, and psychomotor performance measures; (4) document implementation fidelity and the amount of teacher scaffolding required; and (5) examine digital extensions, HMI integration, and SCADA-related tasks only after the core module has demonstrated effectiveness and safe usability.