public function execute() {
        global $CFG, $DB;

        $now = time();

        mtrace(' processing workshop subplugins ...');

        // Now when the scheduled allocator had a chance to do its job.
        // Check if there are some workshops to switch into the assessment phase.
        $workshops = $DB->get_records_select("workshop",
            "phase = 20 AND phaseswitchassessment = 1 AND submissionend > 0 AND submissionend < ?", [$now]);

        if (!empty($workshops)) {
            mtrace('Processing automatic assessment phase switch in ' . count($workshops) . ' workshop(s) ... ', '');
            require_once($CFG->dirroot . '/mod/workshop/locallib.php');
            foreach ($workshops as $workshop) {
                $cm = get_coursemodule_from_instance('workshop', $workshop->id, $workshop->course, false, MUST_EXIST);
                $course = $DB->get_record('course', ['id' => $cm->course], '*', MUST_EXIST);
                $workshop = new \workshop($workshop, $cm, $course);
                $workshop->switch_phase(workshop::PHASE_ASSESSMENT);

                $params = [
                    'objectid' => $workshop->id,
                    'context' => $workshop->context,
                    'courseid' => $workshop->course->id,
                    'other' => [
                        'workshopphase' => $workshop->phase
                    ]
                ];
                $event = \mod_workshop\event\phase_switched::create($params);
                $event->trigger();

                // Disable the automatic switching now so that it is not executed again by accident.
                // That can happen if the teacher changes the phase back to the submission one.
                $DB->set_field('workshop', 'phaseswitchassessment', 0, ['id' => $workshop->id]);
            }
            mtrace('done');
        }
    }