Instructional designers make numerous decisions daily to perform their job, for example, what authoring tool to use, what model or strategy to use, and what design process to use to develop learning solutions. Decision-making is important in the field of instructional design. The literature revealed many factors or variables instructional designers rely on for decision-making including past experience, instructional design models, theories, context or situation, subject matter experts (SMEs), intuition, peers, employer demands, budget, time, and media. The literature also revealed challenges or barriers to decision-making, mainly budget, time, and employer demands. Despite these factors and barriers identified from the research literature, it is still not clear how instructional design decisions are made. There is no clear process for how expert instructional designers make decisions in the workplace. Using the Delphi method, this research sought to examine expert instructional designers' consensus on the list of factors or variables that instructional designers use for decision-making in the workplace and the challenges that expert instructional designers experienced when making instructional design decisions. This study also sought to understand what expert instructional designers propose as a process to guide instructional design decision-making. The findings from the three rounds of iterative questionnaires validated the research findings and also indicated the most important factors instructional designers relied on for decision-making. An artificial intelligence intervention is proposed as a guide and a model to support design decision-making in the workplace. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]