Understanding Items vs. Resources
This article explains the difference between items and resources in Stimaro — two concepts that work together but do different jobs. Getting the distinction clear makes building accurate estimates much easier. For the step-by-step of creating each, see Creating an item sheet and Adding resources to an item.
The short version
A resource is a single cost input — one crew, one machine, one material — applied to a piece of work.
An item is a unit of scope that bundles those resources together into one priced line of your estimate.
Resources are the ingredients. An item is the recipe. You don't bid a job in ingredients; you bid it in recipes.
What a resource is
A resource is one cost component doing one job. It answers a narrow question: how much does this one input cost, applied this many times?
Every resource line has three parts:
- The rate — what one unit of the input costs (a crew's daily rate, a crane's daily rate, a ton of stone)
- The quantity — how many units this piece of work needs (8 days, 8 days, 40 tons)
- The factor — an optional multiplier for things like overtime or adjusted conditions
Multiply them together and you get the resource's contribution: quantity × factor × rate. A resource by itself isn't a bid line — it's one cost driver inside a bigger piece of work.
Resources come in categories that match how your costs actually behave: Labor, Equipment, Rental, Material, Subcontract, and Other. A single piece of work usually needs several at once.
What an item is
An item is a unit of scope — a real piece of the project a contractor would recognize: "furnish and drive steel sheet pile," "demo existing bulkhead," "concrete cap." It's the level you actually think and bid at.
An item is built from its resources. "Drive steel sheet pile" isn't a single number — it's a crew, plus a pile rig, plus the steel, plus maybe a barge, each a resource with its own quantity and rate. Stack those resource lines together and they sum into the item's total cost. Divide by the item's quantity and you get its unit cost.
That's the key relationship: an item's cost is the sum of its resources. Change a resource, and the item's cost changes. The item doesn't carry a price you typed in — it carries a price its resources produced.
Why the two layers exist
You might ask why Stimaro separates these instead of just letting you type a unit price per item. The separation is the whole point, and it buys you three things.
Accuracy you can trace. When "drive sheet pile" costs $520 a foot, you know exactly why — the crew days, the rig days, the steel tonnage, each visible and adjustable. A typed-in unit price is a guess with no story behind it. A built-up item is a number you can defend, line by line, when a customer or a partner asks.
Change in one place, update everywhere. When your crew's wage goes up or fuel spikes, you change the rate once. Every resource using it updates, every item containing those resources updates, and every bid containing those items updates. A flat unit price would have to be hunted down and re-entered everywhere it appears.
Reusable building blocks. A well-built item is a recipe you keep. Your "drive sheet pile" item, with its proper crew and equipment and material resources, can be pulled into any bulkhead bid you ever do — you just change the quantity. Over time your items become a library of how your company actually prices its work.
How they fit with everything else
Items and resources sit in the middle of Stimaro's structure. Beneath them are rates — the unit costs resources draw from. Above them is the bid — where finished items get linked, organized, and marked up into a price.
The flow runs upward: rates feed resources, resources build items, items roll into the bid. The items-and-resources layer is where raw rates become real scope — where "a crew costs $1,800 a day" becomes "driving this bulkhead's sheet pile costs $104,000."
A way to remember it
If it helps, think of it this way:
- A rate is what something costs per unit.
- A resource is that rate put to work — a rate with a quantity attached to a specific item.
- An item is a piece of scope built from several resources.
- A bid is all your items, priced and marked up.
When you're not sure whether you're working with an item or a resource, ask: is this a piece of the job I'd bid (item), or one cost input inside that piece (resource)? "Concrete cap" is an item. The concrete, the rebar, the finishing crew, and the pump that go into it are resources.