Contents
- Choose the process before comparing machine hours
- Calculate cost per accepted part
- Follow the quantity through the route
- Record a build and its downstream operations
- Where additive manufacturing is used
- Advantages and limits for the production route
- Compare additive and conventional routes at one boundary
- What SYMESTIC contributes
- Sources
Additive manufacturing produces a part by adding material in layers from a digital design. The US Department of Energy page calls it another name for 3D printing and notes that stereolithography was patented by Chuck Hull in 1986. For production management the relevant output is the accepted part after every required operation, not the finished print job.
NIST describes the layer-by-layer principle and names metals, plastics and ceramics as materials, often fed as powder or wire. NIST contrasts the principle with cutting or molding, which leave scrap behind. The process route still depends on material, geometry and required properties, and a cost comparison needs the operations after the build: support removal, machining or inspection where the chosen route requires them.
Choose the process before comparing machine hours
The NIST technologies page distinguishes six processes. Powder bed fusion melts powder layers with a laser or electron beam. Directed energy deposition melts material as it is deposited. Material extrusion stacks extruded material and is common in personal and commercial printers. Vat photopolymerization cures liquid resin with ultraviolet light, binder jetting joins powder with a liquid binder, and material jetting deposits droplets that are cured with UV light.
Each route brings different preparation and finishing work, so the comparison should start with the production question, not with the machine.
| Production question | Evidence needed for the comparison |
|---|---|
| Which material and properties are required? | Part drawing and agreed material requirements |
| How many parts fit into one build? | Build layout with the constraints of the chosen process |
| Which operations follow the build? | Defined route through finishing and inspection |
| What makes a part acceptable? | Inspection criteria and the release decision |
| Where can the route queue? | Free capacity at every downstream operation |
A printer with spare hours can still feed a constrained finishing operation. Comparing printer utilization alone hides that queue, so review the whole route before adding a machine or promising a delivery date.
Calculate cost per accepted part
The example is hypothetical and uses a generic monetary unit, so it implies neither a local price nor a supplier quote. One build contains 10 parts. The machine runs 12 hours at an assumed rate of 40 units per hour. Material costs 160 units. Preparation and finishing labor take 3 hours at 50 units per hour, and inspection is charged at 90 units for the build.
| Cost item | Calculation | Units |
|---|---|---|
| Machine | 12 h × 40 | 480 |
| Material | charge for this build | 160 |
| Preparation and finishing labor | 3 h × 50 | 150 |
| Inspection | charge for this build | 90 |
| Total | 480 + 160 + 150 + 90 | 880 |
If all 10 parts pass, the cost is 880 ÷ 10 = 88 units per accepted part. If 2 parts are rejected after the same costs were incurred, 8 accepted parts remain and the result is 880 ÷ 8 = 110 units. The difference of 22 units is a 25 percent increase, and the machine hours have not changed. A comparison based on cost per printed part would not show it.
Fix the boundary of the machine rate before using the calculation. If the rate already contains operator labor or maintenance, do not add those items again. If inspection is charged per part, replace the build charge with the quantity calculation. Include each cost once and name every omission.
Follow the quantity through the route
The drawing repeats the example. All 10 parts leave the build, move through support removal and machining, and reach inspection, where 8 are accepted. The two rejected parts took the same machine, material and finishing time as the others. Reconcile the quantity at every step: each part either continues as accepted work, stays in progress or has a recorded disposition. An unexplained difference is a data question to settle before anyone reports performance.
Record a build and its downstream operations
A build can hold several parts, and sometimes several part types. An order-level total hides it when one item needs more finishing than another. The template separates the shared build information from the part-specific outcomes.
| Record level | Fields to capture | Purpose |
|---|---|---|
| Build | Build identifier, machine, start, end and program revision | Define the shared production event |
| Part or item | Part identifier, quantity and drawing revision | Identify what the build was meant to produce |
| Finishing operation | Operation, input quantity, output quantity and elapsed time | Locate losses after the build |
| Inspection | Accepted quantity, rejected quantity and reason | Establish the usable output |
| Release | Responsible role and release status | Separate completed work from approved delivery |
Add the fields your plant actually uses. The five levels are a starting point for the data requirement you hand to the equipment supplier and to whoever integrates the systems.
Where additive manufacturing is used
NIST names lightweight aerospace structures and customized biomedical implants as applications. Its medical example starts from a 3D model of a patient's bone structure, which is sliced into layers and fed to the machine. The US Department of Energy page traces the technology to Chuck Hull, who developed stereolithography after becoming frustrated with the long production times of prototyping.
Advantages and limits for the production route
NIST states that additive manufacturing can produce complex designs with less material and less waste than traditional manufacturing. The limits show up after the build. The Medibew et al. (2025) review of metal parts says that layer-by-layer deposition may leave visible ridges or staircase steps and unpredictable surface integrity, with higher roughness, hardness and residual stress. Grinding, milling, polishing and similar finishing methods improve surface finish and dimensional accuracy, and the review calls them vital for qualifying such parts for practical use. NIST adds that comprehensive measurements and standards are critical for expanding industrial use.
| Point | What it means for the route | What to record |
|---|---|---|
| Complex shapes with less material | Design freedom can reduce material per part | Material used per build and per accepted part |
| Layer-by-layer surface | Finishing may be needed before the part meets its requirements | Finishing operation, time and result |
| Dimensional accuracy needs checking | Inspection decides whether the part is accepted | Inspection result and reason for each rejection |
| Standards are still developing | Customer or industry requirements may set the proof needed | The requirement and the evidence that meets it |
Compare additive and conventional routes at one boundary
For a route decision, give both alternatives the same required quantity, quality criteria and delivery point, and compare the accepted, finished part. Include setup, material, machine time, finishing and inspection where they apply, and keep one-off tooling charges apart from recurring cost.
A route with a lower initial charge can have a higher recurring cost, and the reverse is possible. A useful comparison therefore states the production quantity and the number of repeat orders it assumes. One cost-per-hour figure cannot settle that choice.
What SYMESTIC contributes
SYMESTIC supplies the production record around the printers and the downstream machines. Machines with OPC UA connect through the Cloud Gateway, free software on your own server or computer, and digital signals through the IoT Box without intervention in the PLC. Stops are detected automatically and carry a reason. Quality inspection is recorded at the workstation per part with its serial number as OK or NOK, with the defect reason chosen from a catalog. That gives the finishing and inspection steps in the table above a quantity and a time instead of an estimate.
Related pages: digital manufacturing and quality control software.
Sources
- NIST: What is additive manufacturing?
- NIST: Additive manufacturing technologies
- US Department of Energy: What is additive manufacturing?
- Medibew, T. M., Zieliński, D., Agebo, S. W., Deja, M. (2025): Recent Research Progress in the Abrasive Machining and Finishing of Additively Manufactured Metal Parts, Materials 18(6), 1249
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