Plexus — POS System & Business Management Software

Helpline & Support

Development Team

Support Information

• Hours: Monday – Friday, 8:00 AM – 6:00 PM EAT
• Response Time: Within 24 hours on business days
• Emergency: For critical outages, call the helpline directly
• Regions Served: East Africa (Uganda, Kenya, Tanzania, Rwanda, Burundi)

Version Control

Security & Licensing

• License: Proprietary — All rights reserved by AlpherTech
• Copyright: © 2026 AlpherTech
• App ID: com.alphertech.plexus
• Data Storage: 100% Local (SQLite) — No cloud sync
• Security: PIN/Pattern/Password lock, session encryption, crash logging

System Requirements

Plexus runs efficiently on most modern Windows computers. Check the requirements below to ensure compatibility.

Windows (Available)

Technology Stack

1. System Overview

Plexus is a comprehensive, locally-run Point of Sale (POS) and Business Management System built by AlpherTech. It combines retail checkout, inventory control, accounting, HR, project management, and reporting into a single desktop application.

Designed for small to medium businesses — agro-input shops, retail stores, and service providers — that need fast, offline-capable transaction processing alongside full business administration.

Key Capabilities

• Fast POS checkout with barcode scanning and category filtering
• Full inventory management with low-stock alerts and expiry tracking
• Customer credit accounts and payment tracking
• Multi-user security with role-based access (Admin, Manager, Cashier)
• Accounting with chart of accounts, journal entries, financial statements
• Purchase order management and stock receiving
• Employee management, leave, shifts, and reimbursements
• Project tracking with tasks, time entries, and attachments
• Multi-warehouse support with stock transfers
• Internal memos and email queue
• Rich reporting: sales, products, customers, Z-reports, weekly PDFs
• Local SQLite database with crash-safe initialization

2. Architecture & Technology

Plexus is built with Flutter for a native desktop experience on Windows (with iOS, Android, macOS, and Linux supported). Data is stored locally in a SQLite database via the sqflite plugin, with Provider for state management.

Core Libraries

Library	Purpose
Flutter / Material	UI framework and components
sqflite / sqflite_common_ffi	Local relational database
Provider	State management and dependency injection
pdf / printing	PDF generation and printing
excel	Spreadsheet export
esc_pos_printer_lts	ESC/POS thermal receipt printing
shared_preferences	Persistent key-value settings
crypto	Password hashing and security
intl	Currency, date, and number formatting
path_provider / file_picker	File system access and backups
window_manager	Desktop window control

Data Flow

All business entities (products, sales, customers, etc.) are managed through dedicated Provider classes that wrap SQLite queries. The UI observes these providers and rebuilds automatically when data changes. Transaction logs and audit records are written to the database for traceability.

3. Installation & Setup

Plexus runs as a standalone desktop application. The installer package is built with inno_bundle.

Requirements

• Windows 10 or later (64-bit recommended)
• 4 GB RAM minimum, 8 GB recommended
• 500 MB disk space
• Thermal receipt printer (optional, for POS printing)

Installation Steps

1. Run the installer Plexus Setup and follow the wizard.
2. Launch Plexus from the Start Menu or desktop shortcut.
3. On first run, the Security Setup screen appears. Create your admin account and choose a lock method (PIN, Pattern, or Password).
4. Complete the security setup to enter the main application.

4. Security & Authentication

Plexus enforces strict security to protect business data. Every user action requiring elevated privileges triggers a password confirmation.

User Roles

Role	Permissions
Admin	Full access to all modules, user management, and system settings
Manager	Access to POS, reports, inventory, most management screens except payroll and system settings
Cashier	POS access and sales viewing only

Lock Methods

• Password — Traditional username and password authentication.
• PIN — Numeric PIN for fast unlock.
• Pattern — Android-style pattern lock.
• Security Question — Backup recovery method.

Session Management

• Press F5 at any time to instantly lock the session.
• Sessions auto-lock after a configurable period of inactivity.
• Locked sessions require the user's PIN, pattern, or password to resume.
• Failed login attempts are tracked. After exceeding the maximum allowed attempts, the account is temporarily locked.

5. Dashboard

The Dashboard is the home screen after login. It provides an at-a-glance view of business health and quick navigation.

Search Bar

Search products by name, SKU, or barcode directly from the dashboard. Results appear instantly, and tapping Sell navigates to the POS with the product pre-focused.

KPI Cards

• Sales — Total sales for today.
• Customers — Total registered customers.
• Low Stock — Count of products below minimum stock levels.
• Profit — Estimated profit from today's sales.

Sales Overview

A 7-day sales table showing daily totals, percentage of total, and summary statistics (Total, Average, Highest, Lowest).

Inventory Summary

Shows total items in stock, total cost value, total selling value, and expected profit/loss across all active products.

Top Products

Lists the first 5 products by name with current stock and selling price.

Quick Actions

One-tap buttons for common tasks: New Sale, Add Product, Add Expense, Backup, Customer Payment, and Reports.

Alerts

Shows low-stock warnings and overdue customer payments. A badge on the Alerts card indicates the total number of active alerts.

6. Point of Sale (POS)

The POS screen is the core transaction module, split into a product grid (left) and a cart summary (right).

Product Grid

• Search — Type to filter by name, SKU, or barcode.
• Category Chips — Filter by category: All, Seeds, Fertilizers, Chemicals, Tools, Other.
• Barcode Scanner — Hardware scanners are supported. The system detects rapid keystrokes (threshold: 50ms) and treats the input as a barcode scan on Enter.
• Tap a product card to add it to the cart.
• Out-of-stock items are greyed out and cannot be added.

Cart

• Displays added items with quantity, unit price, and line total.
• Items can be removed individually.
• Clear All removes every item and resets notes.

Completing a Sale

1. Add products to the cart.
2. Select a payment method: Cash, Credit, Mobile Money, or Bank Transfer.
3. For Credit sales, select a customer. The system validates available credit limit.
4. Tap Complete Sale (F12).
5. A password confirmation dialog appears.
6. On success, a Sale Completed dialog shows invoice number, total, amount paid, and balance due.
7. Choose to Print Receipt or OK to close.

Receipt Printing

Receipts are printed via ESC/POS to the configured thermal printer. The printer IP is stored in app preferences. Sales also generate a transaction log entry and update product stock automatically.

Keyboard Shortcuts (POS)

Key	Action
F2	Focus search
+	Increase item quantity
-	Decrease item quantity
F12	Complete sale
Esc	Clear cart

7. Product & Inventory Management

The Products module manages the full product catalog, pricing, and stock levels.

Product Fields

• Name — Product display name.
• SKU — Stock Keeping Unit for internal tracking.
• Barcode — Scannable barcode for POS.
• Category — Seeds, Fertilizers, Chemicals, Tools, Other.
• Prices — Purchase, Average Cost, Selling, Wholesale, VIP.
• Stock — Current, Minimum, Maximum.
• Units — Base Unit, Selling Unit, Conversion Factor.
• Weight / Volume — Optional per-unit measurements.
• Location & Batch — Warehouse location and batch number.
• Dates — Manufacturing Date, Expiry Date.
• Supplier — Linked supplier for reordering.
• Status — Active / Inactive.

Low-Stock & Expiry Tracking

The system automatically flags products when currentStock <= minimumStock. Expiry alerts appear when products are within 30 days of expiration. These alerts surface on the Dashboard and in reports.

Product CRUD

Navigate to Products from the drawer. Use the add button to create products, tap a row to edit, or swipe/delete to remove. Deletion is soft-delete (the record is preserved for audit).

8. Sales Management

The Sales module provides a historical view of all transactions.

Features

• Sale List — Browse all sales with invoice number, date, customer, payment method, total, and status.
• Filtering — Filter by date range, payment method, or status (Completed, Voided, etc.).
• Void Sale — Voided sales restore product stock and mark the transaction as void. Requires password confirmation.
• Receipt Reprint — Reprint receipts for completed sales.

Sales are automatically linked to cash movements in the accounting module.

9. Customer Management

Manage customer records, credit limits, and payment balances.

Customer Fields

• Name, Phone, Email, Address, ID Number
• Credit Limit — Maximum outstanding balance allowed
• Current Balance — Running total of unpaid credit sales
• Notes

Credit Sales

When a sale is completed on Credit, the customer's balance increases automatically. The POS validates available credit before allowing a credit transaction. Payments received from customers can be recorded from the Customer Payment screen, reducing the outstanding balance.

Overdue Alerts

The Dashboard alerts staff when customers have outstanding balances. The Reports module can filter customers with balances.

10. Supplier Management

Maintain supplier records for procurement and purchase orders.

Supplier Fields

• Name, Contact Person, Phone, Email, Address

Suppliers are linked to products and purchase orders for traceability.

11. Purchasing

The Purchasing module handles the full procurement cycle: Purchase Orders (PO), receiving, and payment.

Purchase Order Statuses

Status	Description
Draft	PO is being prepared
Sent	PO has been sent to the supplier
Partial	Some items received, others pending
Completed	All items received

Workflow

1. Create a PO with supplier, expected date, line items (product, quantity, unit cost), and additional costs (shipping, insurance, customs).
2. Change status to Sent when dispatched.
3. When goods arrive, use Receive Items to record quantities. Stock levels increase automatically.
4. The system updates the PO status to Partial or Completed based on received vs. ordered quantities.
5. Record payments against the PO to track liabilities.

12. Reports & Analytics

The Reports module provides deep insights into business performance. Access it via the drawer or Dashboard Quick Actions.

Date Range

Select a custom date range or use presets: Last 7 Days, Last 30 Days, Last 90 Days.

Tabs

• Overview — Total sales, transactions, average sale value, total profit, net profit (after expenses), total expenses, total tax collected, total discount, total outstanding balance, and number of credit customers.
• Sales — Sales by day, by payment method, and top-selling products.
• Products — Low-stock products and inventory valuation.
• Customers — Outstanding balances and credit customer counts.

Export

Report data can be exported to PDF or Excel for external analysis. Weekly reports are available as dedicated PDF summaries.

13. Z-Reports & Daily Closing

The Z-Report provides an end-of-day financial summary for a selected date.

Z-Report Contents

• Total sales, transaction count
• Sales breakdown by payment method: Cash, Credit, Mobile Money, Bank Transfer
• Cash expected in drawer

Daily Closing

The cashier enters the physical cash count. The system calculates the variance (expected vs. counted). This closing record is saved and cannot be overwritten without a new closing for that date.

14. Accounting

The Accounting module provides double-entry bookkeeping capabilities.

Chart of Accounts

Manage accounts organized by type: Assets, Liabilities, Equity, Revenue, and Expenses. Each account has a code, name, and running balance.

Journal Entries

Create manual journal entries with a debit account and a credit account. The system auto-generates entry numbers (e.g., JE00001). Sales and expenses automatically post to the appropriate accounts.

Bank Reconciliation

Match bank statement lines against recorded transactions to ensure the cash book agrees with the bank balance.

Petty Cash

Track petty cash inflows and outflows. The current petty cash balance is calculated automatically from all transactions.

Financial Statements

• Trial Balance — List of all accounts with debit/credit balances.
• Profit & Loss — Revenue minus expenses over a period.
• Balance Sheet — Assets, liabilities, and equity at a point in time.

15. Human Resources

The HR module manages employee records, time off, shifts, and reimbursements.

Employees

• Personal details: name, email, phone, address, ID number, tax ID, emergency contact
• Employment details: job title, department, hire date, salary, employment type, status
• Bank details: bank name, account number
• Notes and active status

Leave Management

Employees submit leave requests. Managers approve or reject them. Leave types include Annual, Sick, Maternity, Paternity, and Other. The system tracks start date, end date, days, reason, and approver comments.

Shift Scheduling

Create and assign work shifts with dates, times, and assigned employees.

Expense Reimbursement

Employees submit reimbursement claims with amount, category, description, and receipt. Managers review and approve pending claims.

16. Projects

Track project-based work from initiation to completion.

Projects

• Name, description, customer, start/end dates, budget, actual cost, manager, priority, progress, status
• Statuses: Active, On Hold, Completed, Cancelled

Tasks

Break projects into tasks with titles, descriptions, status, priority, start/due dates, estimated vs. actual hours, assignee, and predecessor dependencies. Task progress updates the overall project progress automatically.

Time Entries

Log hours worked against projects and employees for cost tracking and billing.

Attachments

Attach files (quotes, contracts, images) to projects for reference.

17. Warehouses & Stock Transfers

Manage multiple warehouse locations and transfer stock between them.

Warehouses

• Name, code, address, manager, default flag, active status
• One warehouse can be marked as Default.

Stock Transfers

Create transfers from one warehouse to another. The system validates that source and destination are different. Transfers move through statuses: Draft, In Transit, Completed.

Warehouse Stock

Stock levels are tracked per warehouse in the warehouses_stock table. The system supports updating stock counts per product per location.

18. Communication

Internal communication tools keep teams aligned without leaving the system.

Internal Memos

• Create memos with title, content, priority (Normal, High), and optional expiration date.
• Pinned memos appear at the top of the list.
• Only active (non-expired) memos are shown.
• Deleting a memo requires password confirmation.

Email Queue

Queue emails with recipient, subject, body, and optional attachment. The status tracks whether the email is Pending or Sent. This is a lightweight internal email dispatcher.

19. Finances & Expenses

Record and categorize business expenses.

Expense Fields

• Category — Utilities, Transport, Salaries, Supplies, Rent, Maintenance, Other
• Description, Amount, Expense Date
• Payment Method, Reference, Receipt Path, Notes

Expense Analysis

Filter expenses by date range and category. View totals and category breakdowns. Expenses feed into the Reports module for net profit calculations.

20. Settings

The Settings screen is the central configuration hub.

General Settings

• Currency & Formatting — Set currency symbol, position (left/right), and decimal places.
• Date Format — Choose how dates are displayed throughout the app.
• Invoice Settings — Configure invoice prefix (e.g., INV-) and the next invoice number.
• Tax Settings — Set default tax rate and choose tax-inclusive or exclusive pricing.
• Operational Settings — Allow negative stock, require customer on sales, enable/disable F5 instant lock, auto-backup interval.

Security Settings

• User Management — Add, edit, deactivate users; assign roles.
• Change Password — Update your own password.
• Change Lock Type — Switch between PIN, Pattern, or Password.
• Set PIN / Pattern Lock / Security Question — Configure backup lock methods.

System Settings

• Currency & Tax — Manage multiple currencies and tax rates (e.g., VAT). Set defaults.
• System Health — View database status, version info, and diagnostics.
• Backup — Configure automatic backups and manual backup/restore.
• Support — Access help and contact information.

21. Keyboard Shortcuts

Plexus supports keyboard shortcuts to speed up daily operations.

Key	Action	Context
F5	Instant lock	Global
F2	Focus product search	POS
+	Increase quantity	POS
-	Decrease quantity	POS
F12	Complete sale	POS
Esc	Clear cart	POS

22. Data Management

Plexus stores all data locally in a SQLite database. Regular backups are essential to prevent data loss.

Automatic Backup

Configure automatic backups in Settings. The system can back up at regular intervals (default: every 2 hours).

Manual Backup & Restore

Use the Backup screen to manually export the database to a chosen location, or restore from a previous backup file. Restoring replaces the current database with the backup.

Audit Logging

Every create, update, and delete operation is logged in the transaction_log table with user, timestamp, old values, and new values. This provides a full audit trail for compliance and troubleshooting.

Crash Recovery

The app initializes the database in a crash-safe manner. If the app crashes or is closed unexpectedly, it recovers gracefully on next launch and logs the error for diagnostics.

23. Troubleshooting

Common Issues

Issue	Solution
App fails to start	Check the flutter_01.log file in the installation directory for errors. Ensure the database file is not corrupted. Restore from backup if needed.
Printer not connecting	Verify the printer IP in Settings > Receipt Printer. Ensure the printer is on the same network and the IP is correct. Restart the printer and the app.
Barcode scanner not working	Ensure the scanner is configured to send an Enter keystroke after the barcode. The system expects rapid keystrokes (<50ms between characters) followed by Enter.
Cart not restoring after crash	The cart is saved to local preferences. If it fails to restore, check SharedPreferences storage. Clear the cart manually and re-add items.
Database locked / slow performance	Close other apps accessing the database. Ensure backups are not running during peak hours. Consider compacting the database.
User locked out	Use the security question recovery if configured. An Admin can reset the password from User Management. The lockout expires after the configured duration.

Logs & Support

Log files are written to the app's local data directory. When contacting support, include the latest log entries and a description of the steps that led to the issue.