Questions about the purchasing system and BOM module

Hi,
have a few questions about ERPNext:

  1. Is it possible to purchase the system for smaller time frame than a year (monthly cost)?
  2. Is it possible to purchase the system for one year and in the middle of the year to change the purchased package? (if we will see that we have more users, or we need more storage space)

The following questions refer to the window appears when entering a new BOM:
4. The window contains 3 categories (tables): operations, material and scrap. We need 2 more tables like this: fastener and tooling. Is it possible to add them?
5. Operation in BOM: The operation cost is calculated as hour rateoperation time. In my organization the operation cost is calculated as following: unit costquantitymultipliermultiplier value (not all operations have multiplier and multiplier value, in that case the operation value will be just unit cost*quantity). Is it possible to add those fields to each operation and to change the cost calculation method?
6. In the materials table where I should insert quantity, usually my quantity is decimal and not integer, but the current system doesn’t allow inserting fractions. Is it possible to change the fields format to decimal?
7. The current fields in the operation and material tables are not exactly the fields we need. Is it possible to add some more field, as: unit cost, size, area etc.?
8. In the BOM tree display, is it possible when clicking on specific item/BOM to show more details about it? such as name, cost etc.
9. Is it possible for each item in items list to defined 2 different prices? (we need to work by an external price list, but in addition we want to give the item our price, so finally this item will have “external price” and “internal price”).

Is it possible to purchase the system for smaller time frame than a year (monthly cost)?

Standard hosted plans are available on yearly subscription only. Take one month free trial for assurity before subscribing.

Is it possible to purchase the system for one year and in the middle of the year to change the purchased package? (if we will see that we have more users, or we need more storage space)

Sure.

The following questions refer to the window appears when entering a new BOM:
4. The window contains 3 categories (tables): operations, material and scrap. We need 2 more tables like this: fastener and tooling. Is it possible to add them?

You can add it as a Custom Doctype. But if you want any calculation, then custom scripting will also be required.

  1. Operation in BOM: The operation cost is calculated as hour rateoperation time. In my organization the operation cost is calculated as following: unit costquantitymultipliermultiplier value (not all operations have multiplier and multiplier value, in that case the operation value will be just unit cost*quantity). Is it possible to add those fields to each operation and to change the cost calculation method?

May be just skip Operations completely. The qty * rate will give you total material cost anyways.

  1. In the materials table where I should insert quantity, usually my quantity is decimal and not integer, but the current system doesn’t allow inserting fractions. Is it possible to change the fields format to decimal?

It depends on UoM Setting.

https://erpnext.org/docs/user/manual/en/stock/articles/managing-fractions-in-uom

  1. The current fields in the operation and material tables are not exactly the fields we need. Is it possible to add some more field, as: unit cost, size, area etc.?

You can using Custom Fields.

https://erpnext.org/docs/user/manual/en/customize-erpnext/custom-field

  1. In the BOM tree display, is it possible when clicking on specific item/BOM to show more details about it? such as name, cost etc.

Not configurable for now.

  1. Is it possible for each item in items list to defined 2 different prices? (we need to work by an external price list, but in addition we want to give the item our price, so finally this item will have “external price” and “internal price”).

You can maintain multiple price list for the items. Also, you can create multiple BOM for the same FG item, and have different valuation in each BOM.