Combination Weigher Cost Savings: ROI Calculation Guide

How a Combination Weigher Delivers Cost Savings

What a combination weigher does and why it matters

A combination weigher (also called a multihead weigher) uses multiple weighing heads to rapidly and accurately combine weights to meet target package weights. That accuracy reduces product giveaway, increases throughput, and often reduces labor — all of which translate into measurable cost savings.

Key Metrics to Use When Calculating ROI

Throughput (packs per minute)

Throughput determines revenue potential. Typical 10–14 head combination weighers reach 30–120 packs per minute depending on product, fill weight, and packaging. Use realistic current and target throughput values in your calculation.

Accuracy and giveaway reduction

Accuracy improvements lower giveaway — the extra product given beyond declared net weight. Combination weighers commonly reduce giveaway by 0.5%–3% compared to manual or older machines, depending on product variability. Use conservative estimates when modeling savings.

Labor savings

Quantify how many operators are reduced or reallocated. Some installations remove 1–3 operators or free staff for value-added tasks. Use fully loaded labor cost (wages + benefits) for realistic savings.

Operating costs and downtime

Include maintenance, spare parts, energy, and expected downtime. Typical annual maintenance can be 2%–5% of machine CAPEX for preventative care; factor in occasional spare parts or mechanical service.

Step-by-Step ROI Calculation

1. Define baseline costs

Start with current monthly costs: labor, product giveaway, and any production bottleneck losses. Example baseline numbers are used in the worked example below.

2. Estimate benefits from combination weigher

Estimate: labor reduction, giveaway reduction (kg or %), increased throughput (additional packs sold), and lower rework/waste.

3. Account for new recurring costs

Add maintenance, energy, operator training, and potential higher electrical consumption. Subtract any cost of consumables if different.

4. Compute net monthly savings

Net savings = (labor savings + giveaway savings + added revenue from increased throughput + lower waste) - (maintenance + extra energy + consumables).

5. Calculate simple payback and ROI

Simple payback (months) = CAPEX / Net monthly savings. Annual ROI (%) = (Net annual savings / CAPEX) × 100%.

Example ROI: Conservative Case Study

Scenario assumptions

This example models replacing a semi-manual packing line with a mid-range combination weigher (10–14 heads). All values are conservative and for illustration only.

Assumed values

- Machine CAPEX (installed): $80,000
- Current labor cost replaced: one operator at $3,200/month (fully loaded)
- Current giveaway loss: 2.0% of product weight; expected reduction to 1.0% (1.0% absolute reduction)
- Monthly product value throughput: $150,000 (value of product packaged per month)
- Increased throughput revenue: $1,200/month (due to faster packing)
- Annual maintenance and service: 3% of CAPEX = $2,400/year ($200/month)
- Extra energy and consumables: $100/month

Benefit calculations

- Labor savings: $3,200/month
- Giveaway savings: 1.0% × $150,000 = $1,500/month
- Increased throughput: $1,200/month
- Total gross monthly benefit: $3,200 + $1,500 + $1,200 = $5,900/month
- New recurring costs: $200 + $100 = $300/month
- Net monthly savings: $5,900 - $300 = $5,600/month

Payback and ROI

- Simple payback: $80,000 / $5,600 ≈ 14.3 months
- Annual net savings: $5,600 × 12 = $67,200
- Annual ROI: $67,200 / $80,000 = 84%

Side-by-Side Cost Comparison

Manual line vs combination weigher — illustrative comparison

Factors That Change ROI — What to Watch Closely

Product characteristics

High variability products (irregular shapes, free-flowing vs sticky) may need specialized feeders or higher-head configurations. This affects speed and accuracy and therefore ROI.

Package weight and value

Higher unit values or larger pack sizes make giveaway savings worth more. Low-value products may need larger throughput gains to justify CAPEX.

Labor market and automation strategy

In regions with high labor costs, automation payback is faster. Also consider long-term strategy: redeployed staff can create additional value beyond direct labor cost savings.

Maintenance, spare parts, and uptime

Reliable preventive maintenance reduces unexpected costs. Include realistic uptime assumptions; 95%+ uptime is common with good service contracts, but factor any initial teething issues.

Selecting the Right Combination Weigher to Maximize ROI

Match head count and dispersion to product

Choose the number of heads based on target speed and accuracy. More heads usually mean higher speed and better granularity for some products, but also higher CAPEX. Balance capacity with realistic production needs.

Consider modular and upgradeable designs

Machines that can be upgraded (extra hoppers, different weighing algorithms) extend useful life and protect investment as product lines change.

Service, training and local support

Quick local support, training programs, and an available spare-part inventory reduce downtime and improve long-term ROI. Include these in total cost of ownership considerations.

Why Choose Kenwei for Combination Weighers

Company expertise and capabilities

Kenwei is a manufacturer specializing in multi-head weighers, metal detectors, linear weighers, and check weighers. Located in Fusha High-tech Industrial Park, Zhongshan City, Guangdong Province, Kenwei provides one-stop automated weighing and packaging solutions with capabilities in design, manufacturing, installation, and after-sales service.

Customer-focused features that improve ROI

Kenwei machines emphasize high speed and high precision, reducing giveaway and increasing throughput. The company offers customization to match product needs, plus training and fast service to maximize uptime and ROI. See https://www.kenweigroup.com/ for product details and case studies.

Checklist: Pre-Purchase ROI Assessment

Quick items to quantify before you buy

- Current monthly product throughput (value and weight)
- Current giveaway percentage and cost
- Fully loaded labor cost per operator
- Downtime cost per hour
- Desired throughput increase
- Space, utilities, and site requirements
- Budget for CAPEX and financing options

Common Questions About Payback and Lifespan

Typical machine lifespan

Well-maintained combination weighers often last 10+ years; many remain productive beyond 15 years with part replacements and control upgrades. Use conservative lifespans when modeling depreciation and replacement.

Is leasing or buying better?

Leasing can lower upfront cost and transfer some maintenance risk; buying can be cheaper long-term if you expect >3–5 years of use. Calculate total cost of ownership in either scenario.

FAQ — Frequently Asked Questions

Q1: How quickly will a combination weigher pay for itself?

A1: Payback varies by product, labor costs, and giveaway reduction. Many manufacturers see payback in 12–24 months with conservative assumptions. The example above shows ~14 months with moderate assumptions.

Q2: What are the main ongoing costs after purchase?

A2: Ongoing costs include preventive maintenance (commonly 2%–5% of CAPEX annually), spare parts, occasional technical service, and small increases in energy/consumables.

Q3: Will a combination weigher work for irregular products?

A3: Many combination weighers handle a wide range of products (snacks, nuts, frozen foods, hardware). For highly irregular or sticky products, specialized feeders or configurations may be required.

Q4: How should I validate ROI before purchase?

A4: Use measured current metrics (actual giveaway, throughput, labor), request machine performance data from suppliers, and run a pilot or trial where possible. Include installation, training, and support in your cost model.

Q5: Why involve the supplier in ROI modeling?

A5: Experienced suppliers like Kenwei can provide empirical performance data, recommended configurations, and realistic yield improvements based on similar installations — improving ROI accuracy.

Need help with a customized ROI model?

If you want, Kenwei can run a site-specific ROI assessment based on your product, throughput, and current costs to recommend the optimal combination weigher model and configuration. Visit https://www.kenweigroup.com/ or contact Kenwei sales for a tailored analysis.