Project teams expend substantial effort to develop scope definition during the front end planning phase of large, complex projects, but oftentimes neglect to sufficiently plan for small projects. An industry survey administered by the author showed that small projects make up 70-90 percent (by count) of all projects in the industrial construction sector, the planning of these project varies greatly, and that a consistent definition of “small industrial project” did not exist. This dissertation summarizes the motivations and efforts to develop a non-proprietary front end planning tool specifically for small industrial projects, namely the Project Definition Rating Index (PDRI) for Small Industrial Projects. The author was a member of Construction Industry Institute (CII) Research Team 314, who was tasked with developing the tool in May of 2013. The author, together with the research team, reviewed, scrutinized and adapted an existing industrial-focused FEP tool, the PDRI for Industrial Projects, and other resources to develop a set of 41 specific elements relevant to the planning of small industrial projects. The author supported the facilitation of five separate industry workshops where 65 industry professionals evaluated the element descriptions, and provided element prioritization data that was statistically analyzed and used to develop a weighted score sheet that corresponds to the element descriptions. The tool was tested on 54 completed and in-progress projects, the author’s analysis of which showed that small industrial projects with greater scope definition (based on the tool’s scoring scheme) outperformed projects with lesser scope definition regarding cost performance, schedule performance, change performance, financial performance, and customer satisfaction. Moreover, the author found that users of the tool on in-progress projects overwhelmingly agreed that the tool added value to their projects in a timeframe and manner consistent with their needs, and that they would continue using the tool in the future. The author also developed an index-based selection guide to aid PDRI users in choosing the appropriate tool for use on an industrial project based on distinguishing project size with indicators of project complexity. The final results of the author’s research provide several contributions to the front end planning, small projects, and project complexity bodies of knowledge.