Analysis-by-Parts is an older technique by which the individual components of an impact are modeled separately using multiple Events of specific types instead of a single Industry Event. Reasons to use ABP include modifying a spending pattern to better reflect a specific sub-category of an industry (e.g., grape farming vs. fruit farming) or a specific production technique (e.g., dryland farming vs. irrigated farming), or modeling non-profit organizations. Learn more at ABP: Introduction to Analysis-By-Parts.
However, there is an Event Type in IMPLAN called Industry Impact Analysis (detailed) which allows you to enter any values you may have for Wage & Salary Employment, Employee Compensation, and spending on Intermediate Inputs (and also edit the Spending Pattern) or Output. Then, you can enter a zero for Proprietor Employment, Proprietor Income, Taxes on Production & Imports, and Other Property Income to reflect that public and nonprofit organizations are not paying these. And that's it. IMPLAN will calculate the Direct Effect for you so there is no need to use ABP anymore!