private static boolean validateValue(double startTime, int duration, int numPE) {
    	double currentTime = GridSim.clock();
    	boolean valid = true;

        if (startTime < 0.0) {
        	logger.info("Error - start time should be greater or equals to zero.");
        	valid = false;
        }
        else if (duration <= 0.0) {
        	logger.info("Error - duration should be greater than zero.");
        	valid = false;
        }
        else if (Double.compare(startTime, 0.0) != 0 && startTime < currentTime) {
        	logger.info("Error - start time cannot be less than current time.");
        	valid = false;
        }
        else if (numPE < 1) {
        	logger.info("Error - you should reserve at least one PE.");
        	valid = false;
        }

        return valid;
    }