Testimony shall be taken at the hearing and filed with the board. The board upon notice may take further testimony or hear argument. If, upon all the testimony taken, the board shall determine that any person named in the complaint has engaged in or is engaging in any such unfair practice, the board shall state its findings of fact, and issue and cause to be served on such person an order requiring such person to cease and desist from such unfair practice, and to take such reasonable affirmative action, including reinstatement of employes, discharged in violation of Article XII of this act,¹ with or without back pay, as will effectuate the policies of this act. Such order may further require such person to make reasonable reports, from time to time, showing the extent to which the order has been complied with. If, upon all the testimony, the board shall be of the opinion that the person or persons named in the complaint has not engaged in or is not engaging in any such unfair practice, then the board shall make its findings of fact and shall issue an order dismissing the complaint. A copy of such findings of fact, conclusions of law, and order shall be mailed to all parties to the proceedings.