IT Towers
What are IT Towers?
IT towers are groups of technology resources, such as compute, storage, network and end-user devices, used to organize IT costs in TBM. The current TBM Taxonomy calls them technology resource towers.
Updated November 2026 · 6 min read
IT towers are one of the core layers of the Technology Business Management model. They group technology spending by the type of resource it pays for, such as servers, storage, networks, applications and end-user devices. Towers give IT leaders a view of costs that matches how their organization is structured and how their teams think about the technology they run.
In the TBM model, towers sit between cost pools and solutions. Spending enters the model as cost pools, which describe what kind of cost it is, and is then allocated to towers, which describe what resource it supports. From towers, costs flow onward to the solutions and business units that rely on those resources. The current version of the TBM Taxonomy refers to this layer as technology resource towers.
Definition of IT Towers
An IT tower is a category of technology resources that share a common purpose and are usually managed by the same team or function. Each tower is divided into sub-towers that add detail. The Compute tower, for example, separates servers, mainframes, high-performance computing and, since version 5.0 of the TBM Taxonomy, AI compute.
Towers are defined by the TBM Council as part of its standard taxonomy, which makes them consistent across organizations. That consistency is what allows an organization to compare its cost per tower with industry peers and to report on technology resources in a way that new leaders and auditors can follow without learning a local system of categories.
The Standard Towers
In version 5.0 of the taxonomy, the technology resource towers are Data Center, Compute, Storage, Network, Application, Data, Delivery, Tech Management, Security, Risk and Compliance, Smart Devices and End User. These are grouped into broader technology resource domains, such as infrastructure and operations, which provide a summary level above the towers.
Earlier versions of the taxonomy used slightly different towers. Version 5.0 retired the Platform tower and moved its sub-towers into Application and Data, added towers for Data and Risk and Compliance, and introduced new sub-towers for AI, blockchain and smart devices. Organizations moving from an older version need to remap some costs as a result.
Towers Versus Cost Pools and Solutions
Towers answer a different question from the layers around them. Cost pools describe what kind of spending occurred, such as staffing, hardware or cloud services. Towers describe what technology resource that spending supports. A database administrator's salary, for instance, is a Staffing cost that supports the Data tower.
Solutions, in turn, describe what towers deliver to the business. A customer relationship management solution draws on several towers, including Application, Data, Compute and Security. Keeping these layers distinct is what makes the model useful, because each audience can work in the view that suits it while the numbers stay consistent across all of them.
Importance of IT Towers in IT Financial Management
Towers give IT leaders a resource-based view of spending that maps closely to how technology is managed. This makes them the natural level for managing unit costs, planning capacity and comparing performance with peers.
Without towers, IT costs tend to be reported either by general ledger account, which is too financial for most technology decisions, or by application, which hides the shared infrastructure underneath. Towers fill the gap between those two views.
Managing Unit Costs
Each tower can be paired with a measure of consumption to produce a unit cost, such as cost per server, cost per terabyte of storage or cost per end-user device. Unit costs make it possible to see whether a tower is becoming more or less efficient over time.
Tower owners can then set targets based on unit costs rather than total spending. A storage team that doubles capacity while halving its cost per terabyte is performing well, even if its total budget has grown, and unit costs make that performance visible to finance and business leaders.
Benchmarking and Accountability
Because towers follow a standard definition, they are the level at which most IT benchmarking takes place. An organization can compare its spending on the End User tower as a share of total IT spending, or its cost per device, with organizations of similar size and industry.
Towers also support accountability. Each tower usually has a clear owner, such as the head of infrastructure or the end-user services manager, who can be responsible for the tower's costs, unit costs and service levels. This links financial results to the people who can actually change them.
How to Implement IT Towers
Implementing towers involves allocating cost pools to towers and sub-towers using data from across IT. The approach is incremental, starting with costs that are easy to assign and refining the rest over time.
The quality of tower allocations depends heavily on the quality of supporting data, such as asset inventories and labor records. Investing in that data early makes every later step of the TBM model more accurate and easier to defend.
Allocating Costs to Towers
Some costs map directly to a tower. A storage array maintenance contract belongs to the Storage tower, and a network carrier contract belongs to Network. These direct mappings usually cover a large share of non-labor spending and can be automated from vendor and general ledger data.
Other costs need an allocation rule. Shared software licenses might be split by deployment, and data center facilities costs might be split by rack space or power consumption. Each rule uses a cost driver that reflects how the resource is actually consumed.
Allocating Labor
Labor is usually the largest and hardest cost to assign to towers. The most accurate approach uses time tracking or regular surveys showing how staff split their time across resources. Where that data is not available, organizations allocate labor by team, assuming each team works mostly within one tower.
Many organizations start with the team-based approach and refine it later. Even a simple labor allocation is far better than leaving labor unallocated, because staffing is often the largest single cost in each tower and drives much of its unit cost.
Examples of IT Towers in IT Financial Management
The examples below show how towers help organizations understand and manage technology costs.
In both cases, the value comes from combining tower costs with a measure of consumption, which turns a budget figure into a measure of efficiency that can be tracked and compared.
End User Tower Analysis
A company with 8,000 employees calculates that its End User tower costs $16 million a year, or $2,000 per employee. A benchmark shows that similar companies spend closer to $1,600 per employee. Drilling into sub-towers reveals that deskside support costs are well above peers.
The company introduces self-service tools and a remote support model, reducing deskside support costs by $2.4 million a year. Without a tower view, those costs would have been spread across several departmental budgets and the gap would have gone unnoticed.
Storage Unit Cost Trend
An infrastructure team tracks the Storage tower's cost per terabyte each quarter. Over two years, total storage spending rises 30 percent, which initially worries finance leaders, but capacity grows 80 percent over the same period.
The unit cost falls from $420 to $303 per terabyte, showing that the team is delivering much more capacity for each dollar. The tower view turns what looked like runaway spending into evidence of improving efficiency.
Conclusion
IT towers, now called technology resource towers in the TBM Taxonomy, group technology spending by the resources it supports. They connect financial cost pools to the solutions the business uses and give IT leaders a view of costs that matches how technology is managed.
Towers are the natural level for unit costs, benchmarking and accountability. Organizations that allocate costs to towers carefully, especially labor, gain a clear picture of how efficiently each part of IT operates and where the best opportunities for improvement lie.
Related terms
TBM Taxonomy
The TBM Taxonomy is the TBM Council's standard model for classifying technology costs. It organizes spending into cost pools, resource towers, solutions and consumers so costs can be compared and traced.
Cost Pools
Cost pools are groups of costs that share the same type or purpose. In TBM, they form the finance view of technology spending, such as staffing, hardware, software and cloud services.
Unit Cost
Unit cost is the total cost of producing or delivering one unit of a product or service. It equals total cost divided by units and is used to measure efficiency and set prices.
Cost Driver
A cost driver is a factor that causes a cost to change, such as users, transactions or servers. Cost drivers are used to allocate shared costs and explain why spending rises or falls.