Most plant managers will have a rough figure in mind for the cost of a single hour of unplanned ELAU PacDrive line downtime. This will be based on previous breakdowns and typically consider the output rate, direct labour overheads and any emergency call-out fees.
However, this number is not completely accurate. This is not because the individual figures are wrong, but because there are at least seven distinct cost categories. In addition to labour costs for example, contractual retail penalties amongst others need to be included.
The Cost* Model: Seven Categories, One Hour
Category 1: Value of Lost Throughput
This is the starting point and the one most manager calculate first. However, it is frequently underestimated because the wrong variables can often be used.
Formula:
Lost Throughput (£) = Hourly Output Rate (units per hr) × Net Revenue per Unit (£) × Net Margin (%)
Example:
- Line output: 3,200 units per hr
- Net revenue per unit: £0.85
- Net margin: 18%
- Lost throughput value = 3,200 × £0.85 × 0.18 = £489.60/hr
A line producing £2,720/hr of revenue will suffer a delay when it stops if there is no spare shift to run production and reclaim it. Additionally, fixed costs (rent, depreciation and labour overheads) continue regardless of whether the line is working or not. These eat away at margins meaning that any contribution margin will be lost as part of the CoM/CoG calculation.
Category 2: Manufacturing Scrap and In-Process Material Loss
Any unplanned line stoppage is rarely straightforward as there are usually a number of variables to consider. These can include, for example, the machine stopping mid-cycle or the product being packed identified as contaminated.
Spreadsheet Model: Scrap Calculation for ELAU Packaging Lines
| Input Parameter | Variable | Example Value |
| Material in process (kg) | M_in | 47 kg |
| Material cost per kg (£) | C_mat | £3.20 |
| Recovery rate post-fault | R | 35% |
| Product loaded (units) | P_load | 1,840 units |
| Product cost per unit (£) | C_prod | £0.38 |
| Product recovery rate | R_prod | 20% |
Formula:
Material Scrap Cost (£) = M_in × C_mat × (1 − R) + P_load × C_prod × (1 − R_prod)
= 47 × £3.20 × 0.65 + 1,840 × £0.38 × 0.80
= £97.76 + £558.98
= £656.7
This figure does not include the cost of line clearance – which on a food or pharmaceutical line typically requires a supervised clean-down – additional QA sign-off and a re-qualification run before production resumes. In regulated environments this clean-down process alone can extend the effective downtime window by a further 45–90 minutes beyond the actual repair.
Category 3: Idle Labour Cost
Workforce costs continue when a line stops. Operators, line supervisors and quality staff remain on site and can often be unable to be reassigned during an unplanned stoppage – especially in a single-line facility. In such cases these costs can add up to a not inconsiderable figure.
Formula:
Idle Labour Cost (£) = (number of direct staff) × (hourly rate + oncost %) × (downtime hours)
Example:
- 14 direct operators at £13.50/hr + 32% on cost (NI, pension, holiday accrual)
- 2 supervisors at £19.00/hr + 32% oncost
- Idle labour = (14 × £17.82) + (2 × £25.08) = £249.48 + £50.16 = £299.64/hr
On a night shift with an overtime premium of time plus half, the oncost-adjusted figure rises to approximately £415 per hr for the same headcount.
Category 4: Emergency Specialist Call Out
Troubleshooting issues accurately requires specialist knowledge of PacDrive M or PacDrive 3. If engineers onsite don’t have the requisite knowledge and experience then it will be necessary to call on specialists who do. For a plant running a continuous operation, the probability of a breakdown falling outside normal working hours over a 52-week period, assuming random fault distribution, is approximately 73%. This means in the event of a breakdown, there is a greater chance of needing out of hours specialist support.
Unless a service contract is in place a call-out fee is likely to be charged with this being regardless of how long it takes to diagnose the issue or when support is required. The time and day also need to be considered, for example, diagnosing a fault during a Saturday night breakdown would cost more than on a Monday morning.
It should be remembered that if a machine builder’s engineers are required they will often be travelling from overseas which will impact costs. In addition, given the territory they cover, their availability may be limited meaning there is no guarantee of next day attendance.
Overall costs can vary from £1K up to £5K based on today’s figures – a not insignificant amount by any means – with perhaps the most critical factor being how quickly an engineer can attend site.
Category 5: Parts Delivery Premium
PacDrive components are not stocked by general industrial distributors; instead, they are sourced through specialist channels. This means spares can sometimes take longer to obtain – especially obsolete PacDrive M. Specialists such as ourselves do keep stock of key items, but it is still worth considering a Dedicated Stock arrangement for critical parts. It is also highly recommended to ensure you have at least one item in onsite stock of every item of PacDrive equipment used.
When a fault requires a part under the 2am scenario the choices become limited to:
- Option A: Source from a specialist with UK stock. Next-day delivery premium: £45–£180 depending on part size and carrier.
- Option B: Source from European distributors on an approximate 2–3-day lead time.
- Option C: Source a loan unit from a specialist support provider. Availability is dependent upon relationships and any support contracts which might be in place.
The rapid delivery premium can be calculated as follows:
Parts Expediting Cost (£) = [Standard part cost × expedite multiplier] + emergency freight cost + additional downtime cost during sourcing delay
A servo drive sourced at £1,200 on a standard lead time may cost £1,450–£1,800 via emergency channels. The freight alone can be £85–£240 on top of every additional hour the line is down.
Category 6: Retail Contractual Window Late Delivery Penalties
This is the cost many operational budgets do not consider as it sits within the commercial department rather than maintenance. However, it can be triggered directly if line downtime delays deliveries to e.g. FMCG retail customers and has the potential to dwarf every other figure in this model.
Major UK supermarket groups and retail chains operate on tightly contracted delivery windows. A purchase order specifies not just quantity, but also a delivery window. Failure to deliver within that window can lead to penalty clauses which are often enforced without recourse.
Common penalty structures:
| Retailer Category | Penalty Type | Typical Rate |
| Major UK supermarket group | % of invoice value per day of delay | 1–3% of order value per day |
| Major UK supermarket group | Fixed short-shipment fee + % shortfall | £250–£500 fixed + 2% of gap |
| General retailer | Delayed delivery charge | £150–£400 per delivery failure |
| Contract packer (3PL) | SLA breach penalty (per hour late) | £200–£800/hr beyond agreed slot |
Example calculation:
- Purchase order value: £48,000
- Retailer penalty: 2% per day of delay
- 1-hour stoppage causes a 24-hour delivery miss
- Retail penalty: £48,000 × 0.02 = £960 for a single day’s delay
If the delay spans more than one contracted delivery (common when a line stops mid-shift and recovery is not completed before the next pick window), then the penalty can compound per order affected. Two orders delayed by the same fault event comes to £1,920 and three, £2,880.
These penalties are often invoiced automatically and most are non-negotiable under the retailer’s standard supplier’s trading terms. Whilst breakdowns are often unpredictable, the absence of specialist PacDrive support can contribute to delays and their overall cost.
Category 7: Reputational and Relationship Damage
This category is real but much harder to quantify. A single delivery failure will rarely end a supplier relationship. However, if there is a pattern of repeated failures – a greater risk with legacy equipment such as PacDrive M – then the contract could come under pressure. Given these are likely to be in the £millions annually this is something no company would want to put at risk.
The Full Hour: What It Actually Costs
Aggregating the seven categories for the example line used throughout this article:
| Cost Category | 1-Hour Calculation |
| Lost throughput (margin) | £489.60 |
| Scrap and in-process material | £656.74 |
| Stranded labour (nights, 14+2 staff) | £415.00 |
| Emergency engineer (mid-range cost) | £25000.00 |
| Parts expediting premium | £385.00 |
| Retail window penalty (1 order) | £960.00 |
| Total: single-event estimate | £5,406.34 |
What Changes the Arithmetic
The cost we calculated is a standard for a median breakdown, but there are several factors which can increase the total cost substantially:
- Multiple shifts affected: a fault at 22:30 that is not resolved until 06:00 generates nearly eight hours of idle labour costs.
- Orders affected: one breakdown can lead to several missed customer deliveries.
- Regulatory clean-down: in food or pharmaceutical production the downtime clock doesn’t just stop with the mechanical repair.
The Investment That Changes the Equation
At DMC we work with ELAU PacDrive M and PacDrive 3 which are being used daily across packaging, processing and assembly lines. The services we provide are specifically designed to address the cost categories above before they occur:
- Site surveys and condition monitoring: to identify areas of risk onsite and Machine Analyser® to monitor and provide insights into PacDrive equipment health.
- Firmware and hardware compatible spares and loan units: to ensure a fault does not become a sourcing delay adding hours to the cost model.
- Out-of-hours support with ELAU PacDrive specific diagnostic capability: eliminating the emergency call-out premium from an unfamiliar contractor.
- Predictive maintenance planning: to shift ELAU PacDrive interventions from Category 4 (£760 night-rate minimum) to Category 4 avoided entirely.
- Technical training: so on-site teams can handle first-line ELAU PacDrive diagnostics, reducing the time-to-diagnosis window on any shift.
The investment in structured ELAU PacDrive support is not a maintenance cost. It is the alternative to a £5,400 event recurring unpredictably across 52 weeks.
Talk to us before the next fault rewrites your cost model.
(*All costs shown are for illustrative purposes and may not reflect actual values as these are subject to variation according to individual circumstances).