Complex sentence: This overview serves the purpose of stimulating the participants to envision the ultimate final product (software or website), so that the participants would gain the same knowledge and expectations of the ultimate product that product end users are assumed to have.
Split into simpler sentences: This overview serves the purpose of stimulating the participants to envision the ultimate final product (software or website). This would ensure that participants have the same knowledge and expectations of the ultimate product that product end users are assumed to have.