Looks like a cool idea to explore in a bigger game sometime in the future. I've spent some time with it and I think a few simple upgrades would make it better:
When I'm finished with repairing the currently waiting ships, I find myself moving back and forth between the inventory and the orders. I think it would be a good idea to have the current amount of each item displayed in the orders screen, or better yet to integrate those two screens into one.
Several times I was too focused on the part inventory to notice that I was due on rent that time. The "RENT DUE!" notification on the top bar isn't visible enough.
Since the game encourages you to have a surplus of parts (so you can repair all the ships immediately), you can sometimes spend too much and not have enough orders on the final week. This means your game is over before you even press the "END WEEK" button. I think the game would benefit if it would have some form of saving mechanic, like the ability to sell part you have in your inventory for half their original price. Losing half the cost of sold parts would be punishing enough, but the game wouldn't necessarily end after making a single mistake.
Some sort of summary on each new day would be nice. I also think better feedback after clicking the "END WEEK" button could do some good. Imagine if after ending the week the user would be shown a screen where they could see how much they've earned the last week, how much they spent, what parts were used and what parts were bought, are there any ships still waiting to be repaired, etc.
All in all, I think this has the potential to be a very nice manager game. I hope you decide to work on it in the future. :)