Problems arise when the number of products in stock does not correspond with the number of products the information system says the company has in stock. (Sharda & Agrawal, 2012) In order to change that, major changes has to be made when it comes to making continuous improvements and to raise their standards regarding product availability and record inaccuracy (Wild, 2004).

The purpose of this study is therefore designed to identify factors affecting the balance differences and what impact it has on the efficiency of material flow. The demarcation of the work is that Atlas Copco has begun working with Lean and it will not be investigated nor the relationship between balance differences and Lean. The study was based on answering the following questions: What influencing factors can be identified for balance differences? What factors are relevant to the efficiency of material flow? What kind of impact the balance differences has on these factors?

In order to answer the purpose and issues, a theoretical framework has been developed with help of literature studies and an analytical model. The model will be used to see how the company is related to the theory, from the analytical and from the analytical discussion impact factors will appear. The empirical part has emerged from interviews and observations of the case company.

The result that has emerged through the study is that it is a lot of wasteful and unnecessary operations on a daily basis. This is the reason balance differences and inefficacy occurs. Today there is no examination of how large or how often balance differences occur. In order to solve the problems of the working routines, they must be strengthened and better follow-up must be done. The balance differences has to be documented for the personnel to be able to go and do a follow up and investigate on why they occur.

Therefore we conclude from this that the major influencing factor, both for the emergence of balance differences and inefficient material flow is the human factor. Ignorance, carelessness and unnecessary procedures causes that Atlas Copco in Tierp has problems with balance differences and inefficient material flow.