I need your help. I am confused and clueless about the question which layout I should choose.
Explaination about my problem: At the moment I am writting a commodities and account management software for my own e-cigarettes business, btw actually we're offline. Back to problem. I dont know how to design the software. Acutally I have 3 different kinds of areas. The first one is the Costumer area for creating/deleting and maintaining them. The second one is for liquids, flavours and their mixery ratios. And the last one handle the incomes and the costs.
Currently I looks like following, when I start the application I have to choose user- or commodities management. If I choose commodities I can see all of my liquids and for example I could enter the "money" area.
Do you would use another design. I dont have insider information how to design a well-designed program. It is quit difficult for me cause it is also my program which I have to use as my research paper for school.

For all who understands workflow-charts here is mine.
Will be uploaded soon
May you could help me. And sorry for my bad english :S
Best regards,
Halfbax