Introduction: Kiazen is an approach based on common sense that establish small, comprehensive and targeted changes by staff's common wise. Nowadays most successful organizations and companies owe their productivity and dynamicness to implementation of improvement systems such as kiazen. The present research was aimed to introduce and establish of kiazen operational model, and studying its effects on staff's performance in Fars Oil Industry(F.O.I) central policlinic.

Methods: the present study is an interventional study, executed by applying an operational model in F.O.I central policlinic. We used pre & post test method to assess the effects of intervention, using performance questionnaire for 176 studied people in under study organization.

Results: Our findings showed that according to direct chief of studied staffs there is a significant difference between the five performance dimensions: work quality, cooperation, timeliness, innovation and reliability before and after the implementation of the model(p<0.001) indicated the improvements of staff's performance in these dimensions. Although no significant difference were observed in two dimensions work quantity (p=0.61) and work knowledge (p=0.66). 

Conclusion: simplicity and comprehensiveness of kaizen model and simultaneously its dramatic effects on improvement of processes and productivity of work environment has resulted in improvement of staff's performance in under studying organization. This improvement is independent from staff's age, gender, and education. We concluded that kaizen model is extendable to organizational levels, and could result in wide changes in individuals, organizations and even society.