An unsuitable work Environment for the Workforce can be a sign of a high level of risk of internal controls and the client's financial statements. Therefore, it is considered by auditors. The purpose of this study is to investigate the effect of the Workforce Environment on audit fees, auditor report Lags, and audit quality. To test the research hypotheses, 107 companies in the period 2013-2019, equivalent to 749 years-company, were selected and analyzed using multiple regression models. The findings show that audit fees and audit report lags are lower for companies that have provided a favorable working Environment for employees. This suggests that auditors consider such clients to be less risky. As a result, they put less effort into the audit process. Also, the findings of this study show a negative and significant relationship between the Workforce Environment index and audit quality. Also, the findings of this study show a negative and significant relationship between the Workforce Environment index and audit quality.

Shift scheduling is one of the production planning processes that develop organization and Workforces by providing optimized time table. In this study we tried to present mathematical model with minimization function of human errors regarding human factor engineering. Learning, forgetting, fatigue and rest are important factors which increase or decrease human errors and is modeled here. Provided model is nonlinear integer model. To investigate model and study human factors we solved small instances with different parameters in three categories: easy tasks, medium and hard tasks. To solve model we used LINGO software. Results indicated that shift schedules are different regarding different human parameters. With increasing difficulty of tasks and decreasing learning, rest breaks were closer to start of working shift. With decreasing difficulty of tasks and increasing learning, optimized schedule close to schedule without rest breaks. Also results showed that we can use the model to optimize human reliability, and organizations can define optimized shift schedules with considering task types and human parameters.

The purpose of preventive maintenance management is to perform a series of tasks that prevents or minimizes production breakdowns and improves the reliability of production facilities. The inspection, repair, and replacement of production equipment are tasks that are central to preventive maintenance management.An important objective of preventive maintenance management is to minimize the downtime of production facilities. In order to accomplish this objective, management personnel has to efficiently allocate resources and determine an effective maintenance schedule. Mathematical models have been developed to solve the preventive maintenance-scheduling problem of assigning skilled personnel to work with tasks that require a set of corresponding skills.However, there are several limitations in the prior work in this area of research. The craft-combination problem has not been solved because the craft-combinations is assumed to be given. The craft-combination problem concerns the computation of all combinations of assigning multi-skilled workers to accomplishing a particular task. In fact, determining craft-combinations is difficult because of the exponential number of craft-combinations that are possible.This research provides an integrated solution for the preventive maintenance-scheduling problem with multi-skilled Workforce constraints.Two novel preventive maintenance-scheduling model is formulated to automatically produce the optimal solution and craft combination.