The user should be able to save full analysis data (based on the current object model) and store the file on a local disk. The user can then open the app and choose to open a file to load an analysis quickly. This way, the user can quickly compare between several properties and can make decisions quicker without having to enter all data all over again.

The file format can be in XML, or JSON if you're feeling stingy about disk space usage.

Add a "Public Facility" field on the first page. This field is intended for recording how much of the land is allocated for public facilities such as vehicle parking, security guard stations, parks or playgrounds, religious buildings, etc.

Calculation should be as follows:

allotable land area = total land area - total road area - total public space area

Validation should be implemented to prevent unused land areas.

Sometimes the data would not get updated as the user moves back and forth between pages. Need to make sure that all data gets updated on every page change.

May need to add a notification after installation is completed.
Also perhaps it would be better if we can install it in other folder beside the default folder (desktop)

The user should not be able to enter land areas for public use (such as roads and parks) that exceed the total land area. Doing so will cause a negative value for effective land price.

Lots should also be checked, because allocating more than available is still possible.

In Biaya-biaya form, does HARGA TOTAL equal to HARGA SATUAN times VOLUME? If so, wouldn't it be convenient if HARGA TOTAL is filled automatically after VOLUME and HARGA SATUAN are inputted?

In Biaya-Biaya form, I can select multiple "Nama Pekerjaan". But when I click "Hapus Biaya", I can only delete one Biaya. Shouldn't it be able to delete more than one (the selected one) Biaya?

Ensure that all numeric fields have proper decimal and thousand separators. Default format should be 1,000.00. Currently not all fields have that format.

Use Metro-styled "dialog screens" for all notifications.

Add numeric validation on keypress on all numeric fields.

The user should be able to export an analysis to a common file format, such as Word Document, Excel Spreadsheet, or PDF file.

Land purchase costs and land area used for public facilities such as roads and parks are supposed to be fixed costs, determined by the price of the land set in the first page. These two costs should either be changed to a label or protected somehow so they can't be erased/modified.

Make sure the launcher icon shows correctly both on the desktop and in the start menu. This does not appear on Windows 7 Ultimate SP1, but did appear when tested on Windows 7 Professional.

Move all calculation logic from the screen to another class, either in the object model itself or in a business object type of class. This is to separate logic from presentation.

Ini Lokasi dan Luas Properti, I can't delete multiple Lots.

I'm confused on how to use the form, which text box I should input first, which button to press. It will be extremely helpful if there are some sort of help or step by step on each form.

Need to make sure that the application performs full recalculation of all values when the user progresses to the third page, every time.

Make sure all data fields select all text on focus.

Check all dialog boxes to make sure the description includes some basic instructions to on how to proceed.