# Skulitech ERP Code Review and Corrections

**Review date:** 2026-07-24  
**Scope:** Payments, staff expenses, recurring expenses, petty cash, payroll controls, statutory rules, remittances, and P9 reporting.

## Corrections applied

1. **Inactive payroll rules were still being calculated.** Effective-dated and legacy statutory-rule loading now preserves explicitly inactive rules. Employee and employer calculations return zero for inactive rules, including PAYE tax and relief.
2. **Excess deductions could produce an unbalanced payroll journal.** Payroll entry and batch validation now reject total deductions above cash earnings before preparation or posting.
3. **Payroll creation and workflow transitions were vulnerable to stale-status races.** Draft entry creation, preparation, checking, approval, posting, salary payment, remittance payment, and reversal now use transactions, row locks, conditional updates, and affected-row checks.
4. **Reversing payroll did not reverse paid statutory remittances.** Paid remittance journals are now reversed before the payroll journals; pending remittances are cancelled and paid remittances are marked Reversed with audit notes.
5. **Month-end recurring expenses could skip a month.** Recurrence calculation now preserves month-end behavior, including February and leap years.
6. **Expense claim and adjustment workflows could double-process under concurrent requests.** Submission, approval, rejection, payment, reversal, recurring-claim generation, initial adjustment posting, release, and settlement now lock and revalidate their records inside transactions.
7. **Petty-cash reversals could violate fund limits.** Approval and reversal now lock the fund and voucher, recalculate available balance, and prevent overdrafts or maximum-float breaches.
8. **PAYE rates accepted values above 100%.** Server validation, browser constraints, and the integrity checker now enforce rates from 0% through 100%.
9. **P9 totals omitted overtime, arrears, and final dues.** These earnings now flow into monthly aggregation, fallback calculation, display, and annual totals.
10. **Integrity coverage was incomplete.** New checks detect excessive payroll deductions and remittances marked Reversed without a corresponding accounting reversal.

## Files changed

- `bin/check_integrity.php`
- `includes/finance_expense_workflows.php`
- `includes/payroll_enterprise.php`
- `includes/petty_cash.php`
- `modules/hr/hr_documents.php`
- `modules/hr/p9_print.php`
- `modules/hr/payroll.php`
- `modules/hr/payroll_control.php`
- `modules/hr/payroll_rules.php`

No database migration or compiled schema file was changed.

## Validation completed

- PHP syntax: **210/210 passed**
- JavaScript syntax: **3/3 passed**
- Focused regression checks: **23/23 passed**
- Literal `app_url()` references checked: **501; 0 missing targets**
- Literal `__DIR__` include/require references checked: **1,062; 0 missing targets**
- Git whitespace/error check: **passed**
- Corrected ZIP archive integrity: **passed**

Focused checks covered inactive and partial statutory-rule configurations, excessive deductions, monthly and quarterly month-end recurrence, leap-year recurrence, and weekly recurrence.

## Environment limitation

A live MySQL/MariaDB migration, transaction, and browser workflow test could not be run because this review environment has no MySQL/MariaDB server, PDO MySQL driver, or browser-based XAMPP stack. Before production deployment:

```bat
cd C:\xampp\htdocs\college_erp
C:\xampp\php\php.exe bin\migrate.php
C:\xampp\php\php.exe bin\check_integrity.php
```

Back up the application and database first, validate on staging, then test maker-checker approvals, postings, payments, reversals, remittances, recurring month-end generation, petty-cash limits, payslips, and P9 output with authorized test users.
