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How to Create a Network Infrastructure Upgrade Plan

Plan a network infrastructure upgrade with a Gantt chart. Track equipment procurement, staged rollout, testing, and cutover with minimal business disruption.

How to Create a Network Infrastructure Upgrade Plan

The Problem: Network Upgrades Disrupt Business When Done Without a Plan

A network infrastructure upgrade—replacing core switches, upgrading to Wi-Fi 6, migrating from MPLS to SD-WAN, or refreshing firewall hardware—touches every user in the organization. Done well, users notice nothing except that the network is faster. Done poorly, the upgrade takes down email for four hours during a critical business period, or the new firewall configuration blocks applications that the old one permitted.

The most common failure mode is a rushed cutover. The equipment arrives, the network engineer configures it over a weekend, and the business comes back on Monday to a network that mostly works but has five application connectivity issues that take until Thursday to resolve. The second failure mode is missing the change freeze window—scheduling the maintenance window during quarter-end close or earnings week, when any network disruption has immediate financial impact.

A network infrastructure upgrade plan on a Gantt chart maps the full project from procurement through post-cutover monitoring, with maintenance windows scheduled around business-critical periods. gantt-chart.io lets network engineers and IT managers build this plan and share it with the business before the work begins.

Prerequisites

Before building your network infrastructure upgrade Gantt chart:

  • Scope: Which network equipment is being upgraded (core switches, distribution switches, access points, firewalls, WAN edge)
  • Site count: Number of locations being upgraded and their priority order
  • Business calendar: Change freeze dates, earnings periods, peak business weeks
  • Procurement lead times: Network hardware lead times are currently 8-20 weeks depending on vendor and model
  • Network diagram: Current state topology to understand dependencies
  • Rollback capability: Whether old equipment is available for rollback and for how long
  • Maintenance window: Business-approved window for network changes (typically nights or weekends)
  • Application inventory: Critical applications and their network dependencies

Step-by-Step Instructions

Step 1: Set Up the Network Upgrade Timeline

  1. Open gantt-chart.io
  2. Title it "Network Infrastructure Upgrade — [Scope] — [Site(s)]"
  3. Set start date to project approval and end date to 30 days post-cutover
  4. Use Week view for the full project
  5. Immediately add change freeze periods as red task bars before scheduling any work

Step 2: Build the Design and Planning Phase

  1. Create a task group: Design & Planning
  2. Add:
  • Current-state network audit — document all equipment, configurations, VLANs, and IP schemes
  • Future-state network design — new topology, IP addressing plan, VLAN redesign if needed
  • Security policy design — ACLs, firewall rules, NAC policies for new equipment
  • Design review by IT and security — milestone
  • Business impact assessment — document which applications are affected during cutover
  • Design sign-off — milestone (prerequisite for procurement)
  • Maintenance window approval from business — milestone

Step 3: Add the Procurement Track

  1. Create a task group: Procurement
  2. Add:
  • RFQ / vendor selection (if not sole-sourced)
  • Purchase order submitted — milestone
  • Lead time window — duration bar showing expected delivery range
  • Equipment received and inventoried — milestone
  • Equipment tested in lab (if lab environment exists) — 1 week
  • Equipment staged for deployment — milestone
  1. Note: Network hardware lead times from Cisco, Aruba, and Juniper are often 12-20 weeks. Start procurement before design is finalized if hardware is on the critical path.

Step 4: Build the Configuration Track

  1. Create a task group: Pre-Staging & Configuration
  2. Add:
  • Base configuration development (switch templates, firewall policies)
  • Configuration peer review — have a second engineer review all configs
  • Lab testing — test configuration against production traffic patterns if possible
  • Site-specific configuration customization — for multi-site deployments
  • Configuration freeze — milestone (no changes to configuration after this date)

Step 5: Add the Deployment Track

  1. Create a task group: Deployment (one sub-group per site for multi-site)
  2. For each site, add:
  • Pre-cutover testing — verify new equipment is accessible and configured, 1 day before cutover
  • Maintenance window — [Site] — milestone (overnight or weekend window)
  • Old equipment taken offline — milestone
  • New equipment activated — milestone
  • Connectivity testing — first 2 hours of cutover window
  • Application validation — test critical applications across the new network
  • Sign-off by site manager — milestone (business confirms all is working before window closes)
  • Rollback deadline — if issues aren't resolved by this time, revert to old equipment
  1. For a phased multi-site deployment, stagger sites by 1-2 weeks

Step 6: Add Post-Cutover Monitoring

  1. Create a task group: Monitoring & Stabilization
  2. Add:
  • Enhanced network monitoring — 2-week heightened alert threshold window
  • Performance baseline comparison — week 1 vs. pre-upgrade baseline
  • User feedback collection — first 5 business days post-cutover
  • Old equipment held for rollback — duration bar (30 days)
  • Formal project close and documentation update — milestone

Common Mistakes to Avoid

Mistake 1: Procurement Started Too Late

What happens: Design is approved in January. The team plans to order equipment in February for a March cutover. Hardware lead times are 16 weeks. The cutover can't happen until June. The project slips 3 months before a single cable is moved.

How to avoid it: In gantt-chart.io, add the procurement lead time bar immediately after design is started—not after design is approved. For known equipment, you can order based on draft design and cancel or adjust if the final design changes. The alternative is a 4-month hardware wait.

Mistake 2: No Rollback Plan or Deadline

What happens: Cutover begins at 10 PM Saturday. By 3 AM, there are still 6 application connectivity issues. The team keeps troubleshooting. By Monday morning, the office opens to an impaired network. Productivity is lost for two days.

How to avoid it: Define a rollback deadline in the maintenance window: "If connectivity issues aren't resolved by 4 AM, we restore old equipment." Old equipment stays racked and accessible for 30 days post-cutover. Rollback should take 30 minutes, not 4 hours.

Mistake 3: Skipping the Lab Test

What happens: The firewall configuration looks correct on paper. During the production cutover, a specific application uses a non-standard port that wasn't in the application inventory. The firewall blocks it. The cutover window is consumed troubleshooting instead of deploying.

How to avoid it: If a lab environment exists, test the full configuration against realistic traffic. If no lab is available, test in a non-production network segment first. Add Application-specific connectivity testing tasks in the lab phase covering every application on the critical list.

Mistake 4: Skipping the Pre-Cutover Day-Before Check

What happens: The maintenance window starts at 10 PM. At 10:05 PM, the team discovers that the new switch wasn't shipped with the correct IOS version and needs a firmware upgrade. The firmware download takes 45 minutes. The window is now short and under pressure.

How to avoid it: Add a Pre-cutover staging check task the day before each maintenance window. Verify: equipment is racked, powered, and accessible; firmware is at the correct version; configurations are loaded and verified in dry-run mode.

Frequently Asked Questions

Q: How do I plan a multi-site network upgrade?

A: Create a separate deployment task group for each site. Sequence them: start with the lowest-risk site (smallest, fewest users, lowest business criticality) to work out process issues. Apply learnings to subsequent sites. The Gantt chart shows all sites' maintenance windows on one timeline so you can see the full deployment arc.

Q: How long does a campus network upgrade typically take?

A: For a single-building campus network refresh (core and access layer): 3-5 months including procurement. For a multi-site SD-WAN migration across 20 sites: 6-12 months. The limiting factor is usually hardware lead time and maintenance window scheduling.

Q: Who needs to approve the maintenance window?

A: IT leadership, the business owner of the affected site, and any applications teams whose systems will be affected. Document the approval as a milestone in the Gantt chart. If a VP of Operations approved the window, that approval is the shield when someone complains about a Saturday night outage.

Q: What should be in the application validation checklist?

A: List every business-critical application and test: can users authenticate, can they reach the application server, does the application perform at acceptable speed, and do any integrations (printing, file shares, VoIP) work correctly. Run this checklist within the first 30 minutes of the cutover window while you still have time to revert.

Q: How do I handle a SD-WAN migration vs. a hardware refresh?

A: SD-WAN migrations require additional complexity: ISP circuit provisioning (4-8 week lead time), SD-WAN orchestrator setup, routing policy configuration, and usually a hybrid period where MPLS and SD-WAN run in parallel. Add a Parallel operation task bar covering the overlap period when both WAN technologies are active. The Gantt chart for an SD-WAN migration will be 3-4x longer than a hardware refresh.

Summary: Network Upgrade Plan That Minimizes Business Disruption

A network infrastructure upgrade Gantt chart prevents the procurement and cutover surprises that cause extended outages. Here's the structure:

  1. Change freeze windows blocked before any deployment scheduling
  2. Design and planning with business impact assessment and maintenance window approval
  3. Procurement started early, with hardware lead times visible on the chart
  4. Configuration peer-reviewed and lab-tested before production
  5. Deployment with pre-cutover staging checks, application validation, and rollback deadlines
  6. Post-cutover monitoring with old equipment held for 30 days

gantt-chart.io is free and requires no sign-up. Build your network infrastructure upgrade plan today and schedule your maintenance windows before the business calendar fills up.