Financial Data
The Financial Data page defines economic parameters used to bring all life-cycle costs to a common present value and to model financing and price escalation over the analysis period. These values feed directly into the LCCA engine when Calculate is run.
D.1 Overview of the Financial Data page
Click Financial Data in the left navigation menu. The page contains:
- A section header Economic Parameters
- Four required numeric parameters (each with an optional Source text field)
- Action buttons: Load Suggested Values and Clear All
[TODO - screenshot not yet available: documentation_images/partD/01_financial_data_overview.png]
D.2 Economic Parameters
All monetary results in Results and Compare are expressed in the project currency (INR for the example project). The parameters below control how future-year costs are discounted, escalated, and financed.
D.2.1 Field reference
| Field | Required | Input range | Description |
|---|---|---|---|
| Discount Rate | Yes | 0.00–100.00 (%) | Rate used to convert future cash flows into present value. Reflects the time value of money and investment risk. |
| Source: Discount Rate | No | Text | Citation or basis for the discount rate (e.g. government guidance, agency policy). |
| Inflation Rate | Yes | 0.00–100.00 (%) | Expected annual increase in general price levels. Used to escalate costs that occur in future years. |
| Source: Inflation Rate | No | Text | Citation or basis for the inflation assumption. |
| Interest Rate | Yes | 0.00–100.00 (%) | Borrowing or lending rate applied to the financed portion of capital. |
| Source: Interest Rate | No | Text | Citation or basis for the interest assumption. |
| Investment Ratio | Yes | 0.0000–1.0000 | Proportion of total cost financed through investment (equity/debt mix), expressed as a decimal from 0 to 1. Example: 0.5 = 50% of costs financed. |
| Source: Investment Ratio | No | Text | Citation or basis for the financing split. |
Each rate field shows a (%) suffix. Investment Ratio has no percent suffix; enter
0.5for 50%, not50.
Fields marked required must be set before Calculate succeeds. Optional Source fields appear in the generated report when filled.
D.2.2 Role in LCCA
| Parameter | Role in the analysis |
|---|---|
| Discount Rate | Brings maintenance, demolition, traffic, carbon, and other future costs to present value so they can be summed with initial construction cost. A higher rate reduces the present value of distant future costs. |
| Inflation Rate | Adjusts nominal costs that occur in later years of the service life. Works with the discount rate to represent real versus nominal cost streams over the analysis period. |
| Interest Rate | Applies to the financed share of capital. Used when spreading or costing borrowed funds over the life cycle. |
| Investment Ratio | Defines how much of the life-cycle cost stream is treated as investment-financed (0 = none, 1 = fully financed). The complement represents non-investment funding. Typical bridge studies use values between 0.3 and 0.7 depending on funding structure. |
Together, these four values are passed to the calculation engine as GeneralParameters along with bridge life, construction duration, and carbon parameters from other pages.
D.3 Load Suggested Values
Click Load Suggested Values to fill the numeric fields with built-in defaults. The button does not modify optional Source text fields.
Values applied by Load Suggested Values:
| Field | Value |
|---|---|
| Discount Rate | 6.70 % |
| Inflation Rate | 5.15 % |
| Interest Rate | 7.75 % |
| Investment Ratio | 0.5 |
These defaults are starting points for Indian public-infrastructure style analyses. Replace them with project-specific or agency-approved values before final reporting.
After loading, the page marks data as changed and autosaves to the project when the project is saved.
[TODO - screenshot not yet available: documentation_images/partD/02_after_load_suggested.png]
D.4 Clear All
Click Clear All. A confirmation dialog asks whether to reset all fields on this page.
On confirmation:
- All numeric fields return to their minimum (0)
- All text Source fields are cleared
- Validation highlighting is cleared
Clear All affects only the Financial Data page. It does not change Construction Work Data, Bridge Data, or other sections.
D.5 Validation
Validation runs when Calculate is clicked (and when the page’s validate() method is invoked). Results are errors (blocking) and warnings (non-blocking but highlighted).
D.5.1 Required-field errors
The four numeric parameters are required. A spin box still at its minimum value (0) is treated as unset because 0 is the field default.
| Condition | Result |
|---|---|
| Discount Rate, Inflation Rate, Interest Rate, or Investment Ratio left at 0 (initial default) | Error: Required: <field title> - red border |
| User enters any value above the minimum | Required check passes for that field |
To use Load Suggested Values as a fast path, click the button after creating a new project. To enter custom values, type directly into each spin box.
D.5.2 Range warnings
Values above typical public-infrastructure ranges trigger an orange warning border and a verification message. Warnings do not block calculation by themselves; the app prompts for confirmation when warnings are present.
| Field | Warning threshold | Message |
|---|---|---|
| Discount Rate | > 30.00 % | Discount rate exceeds 30% - please verify |
| Inflation Rate | > 25.00 % | Inflation rate exceeds 25% - please verify |
| Interest Rate | > 35.00 % | Interest rate exceeds 35% - please verify |
Investment Ratio has no high-range warning rule. Valid range is enforced by the control: 0.0000–1.0000.
[TODO - screenshot not yet available: documentation_images/partD/03_validation_warning.png]
D.6 Example values - Sone River Road Bridge
For the guide example (India, INR, 50-year design life), use either Load Suggested Values or enter the following explicitly:
Discount Rate : 6.70 %
Inflation Rate : 5.15 %
Interest Rate : 7.75 %
Investment Ratio : 0.5
Source: Discount Rate : MoRTH / RBI long-term guidance (example)
Source: Inflation Rate : CPI-based assumption (example)
Source: Interest Rate : Lending rate assumption (example)
Source: Investment Ratio: 50% financed (example)
Source text is optional. Use it to document assumptions for peer review and PDF reports.
D - Screenshot checklist
| Checklist Item | File |
|---|---|
| Financial Data - Overview (annotated) | documentation_images/partD/01_financial_data_overview.png |
| After Load Suggested Values (annotated) | documentation_images/partD/02_after_load_suggested.png |
| Validation warning - high discount rate (annotated) | documentation_images/partD/03_validation_warning.png |