Top 10 IT Infrastructure Mistakes Small Businesses Make

After years of working with small manufacturers, aerospace contractors, and professional services firms, we've seen the same IT infrastructure mistakes repeated over and over. These aren't just annoyances—they lead to downtime, security breaches, lost productivity, and failed compliance audits. Here are the top 10 mistakes and how to avoid them.

Mistake #1: No Documentation

What we see: Network diagrams don't exist. Nobody knows the password for the firewall. The "IT guy who set everything up" left three years ago and took all the knowledge with him. When something breaks, it takes hours just to figure out how the system is supposed to work.

The real cost:

• Extended downtime during outages (hours instead of minutes)
• Expensive emergency consulting to reverse-engineer your own network
• Failed compliance audits requiring documented procedures
• Inability to onboard new IT staff or vendors efficiently
• Security risks from forgotten accounts and unknown systems

The fix:

• Create and maintain a network diagram (update it quarterly)
• Document all IP addresses, VLANs, and subnets
• Use a password manager for all credentials
• Maintain an asset inventory (hardware and software)
• Document standard procedures for common tasks
• Store documentation in a central, accessible location

Mistake #2: Treating Backups as "Set and Forget"

What we see: Backup software was installed years ago, shows green checkmarks, but nobody has ever tested a restore. Or the backup drive filled up six months ago and nobody noticed. Or backups run, but they're backing up to a drive on the same server—useless if the server dies.

The real cost:

• Complete data loss during hardware failure or ransomware attack
• Days or weeks of downtime trying to recover
• Lost customer data, engineering files, and financial records
• Business closure (60% of small businesses close within 6 months of major data loss)

The fix:

• Follow the 3-2-1 rule: 3 copies, 2 media types, 1 offsite
• Test restores quarterly—actually recover files and verify they work
• Monitor backup jobs daily (automate alerts for failures)
• Keep backups separate from production systems
• Document your recovery procedures and test them
• Consider immutable backups that ransomware can't encrypt

Mistake #3: Flat Network Architecture

What we see: Everything on one network—office computers, production equipment, security cameras, guest WiFi, servers. One compromised laptop means attackers can reach every system in the building.

The real cost:

• Ransomware spreads from one infected PC to entire network
• Production systems affected by office network problems
• Guest devices on same network as sensitive data
• Failed CMMC/NIST compliance audits
• Inability to control traffic between different systems

The fix:

• Segment network into VLANs (office, production, servers, guests)
• Implement firewall rules between segments
• Isolate production/shop floor equipment
• Create separate guest WiFi with internet-only access
• Control and monitor traffic between zones
• Consider creating a CUI enclave for controlled data

Mistake #4: No Multi-Factor Authentication

What we see: Password-only protection for email, VPN, cloud services, and admin accounts. Often with weak passwords that haven't changed in years. Sometimes the same password used across multiple systems.

The real cost:

• Account takeover from phishing attacks
• Business email compromise leading to fraudulent wire transfers
• Attackers accessing systems with stolen credentials
• Failed compliance requirements (CMMC, cyber insurance)
• Data breaches exposing customer information

The fix:

• Enable MFA on ALL accounts, starting with admins and executives
• Use authenticator apps (not SMS) for better security
• Enforce MFA for remote access (VPN, RDP)
• Apply MFA to cloud services (Microsoft 365, Google Workspace)
• Implement conditional access policies where available
• Train users on why MFA matters and how to use it

Mistake #5: Running Outdated Systems

What we see: Windows Server 2008 or 2012 still running critical applications. Windows 7 workstations because "the software only works on that version." Firewalls and switches with firmware from 2015. Software with known vulnerabilities that haven't been patched in years.

The real cost:

• No security updates for known vulnerabilities
• Easy exploitation by automated attack tools
• Incompatibility with modern security tools
• Compliance failures (can't meet security requirements)
• Eventually, catastrophic failure with no support available

The fix:

• Inventory all systems and identify end-of-life dates
• Create upgrade plan with timeline and budget
• Isolate legacy systems that can't be upgraded immediately
• Implement compensating controls around old systems
• Enable automatic updates where appropriate
• Establish patch management procedures (monthly patching)

Mistake #6: Everyone is an Administrator

What we see: Every employee has local admin rights on their computer "because they needed to install something once." Multiple Domain Admin accounts, including for people who left years ago. Service accounts with Domain Admin rights because it was easier than figuring out the actual permissions needed.

The real cost:

• Malware runs with full system access
• Users accidentally (or intentionally) damage systems
• Unauthorized software installations creating vulnerabilities
• Compromised accounts have maximum impact
• No audit trail of who did what

The fix:

• Remove local admin rights from standard users
• Use separate admin accounts for IT staff
• Limit Domain Admins to 2-3 accounts maximum
• Implement LAPS for local administrator passwords
• Grant service accounts only the permissions they need
• Review and remove unnecessary admin accounts quarterly

Mistake #7: No Disaster Recovery Plan

What we see: Backups exist, but nobody knows how to restore them. No plan for what to do if the server room floods or catches fire. No documented procedures for getting business-critical systems back online. Assumptions that "we'll figure it out" during an emergency.

The real cost:

• Extended downtime (days/weeks instead of hours)
• Panic decision-making during crisis
• Missing equipment, credentials, or documentation needed for recovery
• Lost revenue during extended outages
• Permanent business closure in worst cases

The fix:

• Document Recovery Time Objectives (RTO) for each system
• Create step-by-step recovery procedures
• Maintain offsite copies of critical documentation
• Identify what hardware/resources you'd need to recover
• Test disaster recovery procedures annually
• Consider cloud-based disaster recovery for critical systems

Mistake #8: Relying on Consumer-Grade Equipment

What we see: Netgear routers from Best Buy as the company firewall. Consumer WiFi access points for a 50-person office. USB hard drives as the backup solution. Residential internet connections without failover.

The real cost:

• Frequent failures and instability
• No security features (logging, VPN, intrusion detection)
• Poor performance under business workloads
• No management capabilities or centralized control
• Voided compliance requirements
• No vendor support when problems occur

The fix:

• Invest in business-grade firewall (Fortinet, SonicWall, Cisco Meraki)
• Use enterprise access points with central management
• Deploy business-class backup solutions
• Consider redundant internet connections
• Use business-grade switches with VLAN support
• Budget for proper equipment—it's cheaper than downtime

Mistake #9: No Security Awareness Training

What we see: Employees clicking on phishing links because they don't know what to look for. Passwords written on sticky notes. Sharing credentials via email. Plugging in found USB drives. No understanding of social engineering tactics.

The real cost:

• Successful phishing attacks leading to breaches
• Business email compromise and wire fraud
• Ransomware infections from careless clicks
• Data leaks from improper handling
• Failed compliance audits requiring training documentation

The fix:

• Conduct security awareness training at hire and annually
• Run simulated phishing campaigns to test and train
• Establish clear policies for handling sensitive data
• Make reporting suspicious emails easy (dedicated address or button)
• Share real examples of attacks (without shaming individuals)
• Reward employees who catch and report threats

Mistake #10: Treating IT as a Cost Center Instead of Business Enabler

What we see: IT budget cut first when money is tight. Cheapest option always chosen. Reactive "fix it when it breaks" approach. No strategic planning or investment. IT decisions made without understanding business impact.

The real cost:

• Chronic underinvestment leading to fragile infrastructure
• Productivity losses from slow, unreliable systems
• Security breaches that cost 10x what prevention would have
• Inability to adopt technologies that competitors are using
• Lost contracts due to compliance failures
• Emergency spending that exceeds what planned upgrades would cost

The fix:

• View IT as investment in productivity and security
• Calculate true cost of downtime (lost production, missed deadlines)
• Create multi-year technology roadmap
• Budget for planned upgrades instead of emergency replacements
• Align IT investments with business goals
• Include IT in strategic business planning

The Common Thread

Notice what these mistakes have in common: they're all about short-term thinking. Skipping documentation saves time today but costs days during recovery. Avoiding MFA is convenient until accounts are compromised. Consumer equipment is cheaper upfront but fails when you need it most.

The businesses that avoid these mistakes share a different mindset. They understand that:

• Prevention is cheaper than recovery
• Downtime has real costs (even if not on the income statement)
• IT infrastructure is business infrastructure
• Security isn't optional—it's a business requirement
• Planning beats reacting every time

How to Get Started

If you recognized your business in several of these mistakes, don't panic. You can't fix everything at once, but you can start making progress:

This Week:

• Enable MFA on all admin accounts
• Verify your backups are actually running and completing
• Change any default passwords you know about

This Month:

• Conduct a basic inventory of systems and accounts
• Test a backup restore (pick one critical file/system)
• Identify your most critical systems and their recovery requirements

This Quarter:

• Roll out MFA to all users
• Create or update network documentation
• Identify and plan upgrades for end-of-life systems
• Evaluate network segmentation options

This Year:

• Complete network segmentation project
• Establish regular patch management procedures
• Implement security awareness training program
• Create and test disaster recovery plan
• Develop multi-year technology roadmap

The Bottom Line

Every business makes IT infrastructure mistakes. The difference is whether you identify and fix them proactively or wait until they cause a crisis. These ten mistakes are common because they're easy to make—especially when you're focused on running your business, not managing IT.

For small manufacturers and aerospace contractors, the stakes are particularly high. Production downtime means missed deliveries. Security breaches can mean lost contracts and compliance failures. The cost of getting IT wrong far exceeds the investment in getting it right.

Start where you are. Fix the most critical issues first. Build from there. Your future self—and your business—will thank you.