Add ONPREM_ARCHITECTURE

ONPREM_ARCHITECTURE

@@ -0,0 +1,224 @@
+# On-Premises System Architecture
+
+## Overview
+
+This document describes the architecture for the **on-premises deployment of the application system**.
+
+The system is hosted entirely within the company's internal infrastructure and is **not dependent on cloud services**.
+
+The design prioritizes:
+
+* local control of infrastructure
+* internal network performance
+* simplified deployment
+* managed backups through **CBM Technology**
+
+High availability and cloud failover are **not included** in this architecture.
+
+---
+
+# Architecture Overview
+
+```mermaid
+flowchart TB
+
+USER[Internal Users]
+
+LAN[Company Network]
+
+APP[On Prem Application Server]
+
+DB[(Primary Database)]
+
+BACKUP[CBM Backup System]
+
+USER --> LAN
+LAN --> APP
+APP --> DB
+
+APP --> BACKUP
+DB --> BACKUP
+```
+
+---
+
+# System Access
+
+The application is accessed through the **internal network**.
+
+Example:
+
+```
+http://app.local
+```
+
+or
+
+```
+http://server-name
+```
+
+Remote access may be provided through a **VPN connection**.
+
+```mermaid
+flowchart LR
+
+USER[User Device]
+
+VPN[VPN Connection]
+
+LAN[Company Network]
+
+APP[Application Server]
+
+DB[(Database)]
+
+USER --> VPN
+VPN --> LAN
+LAN --> APP
+APP --> DB
+```
+
+---
+
+# Infrastructure Components
+
+## Application Server
+
+The on-premises server hosts the application software.
+
+Responsibilities include:
+
+* serving the web interface
+* processing application logic
+* connecting to the database
+* managing file storage if required
+
+Typical deployment:
+
+* Windows Server or Linux server
+* Web server (IIS, Nginx, or Apache)
+* Application runtime environment
+
+---
+
+## Database Server
+
+The database stores all operational data for the application.
+
+Examples of stored data:
+
+* inventory records
+* application configuration
+* user accounts
+* transaction history
+
+In smaller deployments the database may run on the **same server as the application**, though separating them can improve performance.
+
+---
+
+# Network Layout
+
+The application resides inside the company LAN.
+
+```mermaid
+flowchart TB
+
+USERS[Internal Workstations]
+
+SWITCH[Network Switch]
+
+SERVER[Application Server]
+
+DB[(Database)]
+
+USERS --> SWITCH
+SWITCH --> SERVER
+SERVER --> DB
+```
+
+Access is restricted to internal users or remote users connected via VPN.
+
+---
+
+# Backup System
+
+Backups are managed by **CBM Technology** to protect against hardware failure, data corruption, or accidental deletion.
+
+```mermaid
+flowchart LR
+
+APP[Application Server]
+
+DB[(Database)]
+
+CBM[CBM Backup Storage]
+
+APP --> CBM
+DB --> CBM
+```
+
+Backups typically include:
+
+* full server snapshots
+* database backups
+* file storage backups
+
+---
+
+# Backup Schedule
+
+Typical backup configuration:
+
+| Backup Type         | Frequency             |
+| ------------------- | --------------------- |
+| Database Backup     | Daily                 |
+| Server Snapshot     | Daily                 |
+| File Storage Backup | Daily                 |
+| Retention Period    | Defined by CBM policy |
+
+Backups are stored **offsite** to protect against local disasters.
+
+---
+
+# Disaster Recovery
+
+If the system fails due to hardware issues or data corruption:
+
+1. The affected server is repaired or replaced.
+2. The most recent backup is restored by **CBM Technology**.
+3. Application services are restarted.
+4. Users reconnect to the system.
+
+Recovery time depends on:
+
+* server replacement time
+* backup restoration duration
+* database size
+
+---
+
+# Limitations of This Architecture
+
+Because the system is **single-site and non-redundant**, the following events may cause downtime:
+
+| Event                   | Result                                 |
+| ----------------------- | -------------------------------------- |
+| Server hardware failure | Application unavailable until restored |
+| Power outage            | System offline                         |
+| Network switch failure  | Users unable to access server          |
+| Database corruption     | Restore from backup required           |
+
+---
+
+# Potential Future Improvements
+
+If higher reliability is required, the architecture could be expanded to include:
+
+* secondary application server
+* database replication
+* network redundancy
+* uninterruptible power supply (UPS)
+* offsite disaster recovery infrastructure
+
+These additions would move the system toward a **high availability architecture**.