A job shop or engineer-to-order (ETO) manufacturer should require an ERP that quotes from estimates, holds a bill of materials and routing per job with revision control, costs each job against its estimate, plans materials for one-offs and captures shop-floor time as work happens. Test each with your own jobs, not a demo script.
Repetitive manufacturers build the same product on a schedule. Job shops and ETO manufacturers build to a customer drawing or specification, often once. That changes what the software must do: the bill of materials is not stable, the routing is partly guessed at quote time, and the margin lives or dies on how well the estimate matches what actually happened. This guide is about those requirements. It is separate from our broader manufacturing ERP software page and from the general how to choose ERP for a small manufacturer guide, which cover the repetitive and mixed-mode cases.
Key takeaways
- Treat the job as the central record. Quote, bill of materials, routing, purchasing, time, scrap and invoice should all hang off one job number.
- Require revision control on bills of materials and routings, with the revision that was released to the floor recorded on the work order.
- Material requirements planning (MRP) must be able to peg demand to a specific job, so a purchase for job 4127 is not consumed by job 4130.
- Job costing is only useful if you can compare estimate, committed and actual cost while the job is still running.
- If you already have an ERP, ask first whether a planning or shop-floor layer can sit beside it, and what the integration must carry.
- Test every vendor, including a custom build, with three of your real jobs.
What engineer-to-order and job costing capabilities do custom manufacturers need?
Custom manufacturers need eight capabilities in one connected flow: estimating and quoting, configurable or job-specific bills of materials, routings with setup and run times, purchasing linked to jobs, shop-floor reporting, job costing against estimate, engineering change control and invoicing or milestone billing. The table shows what to ask for each.
| Capability | What to require | Question to put to any vendor |
|---|
| Quoting | Estimate built from materials, labour hours, outside processing and margin; versions kept | Can a won quote become a job without re-keying? |
| Bill of materials | Job-specific BOM, copy from a similar past job, multi-level, with revisions | What happens to open purchase orders when the BOM changes? |
| Routing | Operations, work centres, setup and run time, outside operations | Can the routing be edited per job without changing the master? |
| Purchasing | Requisitions and purchase orders tagged to the job | Can I see committed cost by job before goods arrive? |
| Shop floor | Time, quantity, scrap and status by operation | Can an operator report from a tablet or a barcode scan? |
| Job costing | Estimate, committed and actual, by cost type | Is cost visible mid-job, not only at close? |
| Change control | Engineering change request, approval, effect on cost and delivery | Who is notified when a change touches a released job? |
| Billing | Progress or milestone invoices, deposits, final invoice | Can billing follow the contract, not just shipment? |
How should quoting work when you have never made the product before?
Quoting for a one-off job should build the price from a structured estimate: material lines, operations with hours at a stated rate, outside processing, freight, a contingency and a margin. The system should let you copy a similar past job as a starting point and keep every quote version, so that a win converts directly into a job.
The most useful quoting feature is not the calculator. It is the link back to history. For example (illustrative), if you quote a welded frame at 38 hours and similar frames have averaged 46 hours across your last six jobs, the system should be able to show you that before you send the quote. That requires actual hours to be stored against operation types and job families, which is a data design question you should raise early.
Also require quote lines that become the job's cost budget by cost type (material, labour, subcontract, other), and a record of lost quotes with the reason.
Routings and BOM revisions for one-off jobs
A job-shop routing lists the operations a job passes through, with the work centre, setup time and run time for each. In ETO work the routing and the bill of materials are usually created or edited per job, so the ERP must allow job-level changes without disturbing master data, and must record which revision was released to the shop floor.
Revision control matters because drawings change after work has started. When the customer changes a bracket from 6 mm to 8 mm plate, a good system will:
- Raise a change request against the job and the affected assembly.
- Show what is already purchased, cut or issued for the old revision.
- Estimate the cost and delivery effect of the change.
- Record who approved it and when, and release the new revision to the floor.
- Mark the old revision superseded, so operators cannot pick up outdated paperwork.
Ask a vendor to demonstrate steps 2 and 5 on a job that is already in progress, because a revision on a quiet job proves little.
Can an ERP run MRP for job shops and one-offs?
Yes, but the planning logic differs from repetitive manufacturing. For make-to-order work, MRP should plan materials from the job's own bill of materials and peg each requirement to the job that needs it. Stock held for a job should stay allocated to it, and shared stock should be planned with normal reorder logic.
In practice three modes are needed side by side:
| Planning mode | Used for | What the system should do |
|---|
| Job-pegged (make to order) | Custom parts and assemblies | Create requirements and purchase suggestions tied to the job and due date |
| Stocked, reorder-point | Fasteners, consumables, standard plate and bar | Replenish on min and max levels, not per job |
| Mixed | Standard components inside a custom assembly | Use stock first, then buy for the shortfall, keeping the job reference |
Be wary of any system that offers only one mode. A job shop that runs everything through reorder points over-buys; one that pegs everything to jobs loses the benefit of buying standard material in bulk. See the ERP inventory management module guide for how stocked items are controlled.
Job costing: estimate versus actual while the job is still running
Job costing should capture material issued, labour hours at the cost rate of the person or work centre, outside processing, scrap and an overhead allocation, and compare them with the quote by cost type. The point is early warning: you want to learn that a job is 20 hours over at 60 percent complete, not at invoicing.
Require these views:
- Estimate versus committed versus actual for each job and each cost type.
- Work in progress (WIP) valuation by job at any date, which your accountant will ask for at month end.
- Variance by reason, such as extra setup, rework, price change or a design change.
- Margin by customer and by job family, so pricing can be adjusted.
Overhead allocation is a policy decision for you and your accountant, per labour hour, per machine hour or as a percentage of material; the software must support the choice and show the rate used.
Shop-floor reporting: what to capture and how
Shop-floor reporting should record start and stop times, quantities good and scrapped, and the reason for any delay, by operation and by person or machine. Capture should take seconds: a barcode scan on the job traveller, a tablet at the work centre or a terminal at the machine. Data entered at the end of the week from memory will not support job costing.
Keep the data set small so operators actually use it: job and operation, who, start, stop, quantity good, quantity scrapped, and a short reason list. If parts of the shop floor have no connectivity, ask about offline capture.
What are the options for production planning without replacing your ERP?
If you already run an ERP and manage several production lines, you have three realistic options: configure the ERP's own scheduling better, add a planning and scheduling layer that reads orders from the ERP and writes dates back, or build a focused custom module. A full replacement is the last option, not the first.
| Option | Good when | Watch out for |
|---|
| Better use of the existing ERP | Planning data is poor, not the software | Time spent on clean-up, not new tools |
| Add-on scheduling or shop-floor layer | The ERP handles money well but scheduling poorly | Two systems must agree on routings, capacities and order status |
| Custom module on top of the ERP | You have specific rules (tooling, operator skills, customer priority) no add-on handles | A defined data contract and someone to own it |
| Replacement | The ERP cannot be extended or is unsupported | Cost, risk and time |
Whatever you choose, define the data contract before buying. List which system owns each record (items, BOMs, routings, work centres, orders, calendars), which fields flow in which direction, how often, and what happens when the two disagree. Our ERP integration services page and the system integration approaches guide describe the patterns. For a 200-person plant with several lines, the first question is rarely software: it is whether routings and standard times in the ERP are accurate enough to schedule from.
What data do we need ready before migrating work orders to new manufacturing software?
Before migrating work orders, prepare the open orders with their status, the released bill of materials and revision, the routing with operations completed, material issued and still to issue, labour reported to date, outside operations in progress and the WIP value at the cutover date. Closed history can usually be archived rather than migrated.
Use this checklist:
| Data | Why it matters | Typical decision |
|---|
| Open work orders and status | The shop must carry on without gaps | Migrate all open orders |
| BOM and revision at release | Operators build to the released revision | Migrate released revision, archive others |
| Routing and operations completed | Remaining hours drive the schedule | Migrate with completed flags |
| Material issued and outstanding | Prevents double issue or shortage | Reconcile to physical stock first |
| Labour and cost to date | Job cost must continue unbroken | Load as an opening balance by job |
| Linked purchase orders | Commitments must not vanish | Migrate open lines |
| Customer and due dates | Delivery promises | Migrate and re-verify |
Finish open work orders where you can before cutover, because fewer open jobs means fewer opening balances to reconcile. The ERP data migration checklist covers rehearsals and reconciliation in more depth.
Which ERP systems are worth considering for manufacturers that have outgrown basic software?
The right shortlist depends on how you make things, so rank by fit rather than by brand. Manufacturers that have outgrown basic accounting or spreadsheet software should consider three groups: packaged manufacturing ERPs, configurable platforms with a manufacturing module, and a custom ERP built around the job process. Score each against your own jobs.
Use a weighted score and keep it honest. Typical criteria and example weights, which you should change to suit you, are shown below.
| Criterion | Example weight | How to test |
|---|
| Job-level costing with estimate versus actual | 20 | Run one finished job through |
| Revision control on BOM and routing | 15 | Change a released job mid-run |
| Job-pegged MRP | 15 | Plan a one-off with shared stock |
| Shop-floor capture | 15 | Operator completes a day of entries |
| Integration with accounting, CRM, CAD or PLM | 15 | Ask for the data contract |
| Reporting your managers read | 10 | Rebuild your weekly report |
| Total cost over five years | 10 | Include licences, support and changes |
Illustrative example: one custom machine frame
The numbers below are illustrative, not benchmarks. A job shop quotes a machine frame at 140 labour hours, 3,200 of material and 900 of outside painting. The quoted cost is 140 hours at 55 per hour (7,700) plus 4,100, which is 11,800, and the job is priced at cost plus 20 percent. Part way through, the customer changes a mounting plate, adding 6 hours and 150 of material, so the cost budget becomes 146 hours, 3,350 of material and 900 of painting: 12,280. When the fabrication milestone, planned at 90 of the 146 hours, is reported complete, 96 hours are booked, so it is 6 hours over plan. The plate should be charged to the customer through a change order, and the remaining overrun is visible now, so the planner can check whether it came from setup or rework while the job can still be corrected. Without mid-job costing the same overrun would have appeared after invoicing, when it can only be explained, not recovered.
When this is the wrong approach
A full ETO-grade ERP is the wrong approach when you make a small range of repeat products, when job costing is not how you price, or when your real problem is bad data. A 15-person shop with stable products and accurate standard times may do better with simpler scheduling and an accounting package. If routings and times in your current system are wrong, a new system will schedule wrongly faster. Fix the data before you buy.
Glossary: ETO, engineer-to-order, where each order needs engineering before manufacture; BOM, bill of materials; routing, the ordered operations to make an item; MRP, material requirements planning; WIP, work in progress; pegging, tying a requirement to the demand that caused it; ECN, engineering change notice.
How Timeline Digital approaches job shop and ETO systems
Job shops often find that a packaged ERP fits only part of how they quote and cost work. Timeline Digital, founded in Islamabad in 2013 and delivering remotely, can build custom ERP software around your job process. In the Plan step we review your quote, routing and costing practice, and we build a free pilot of two to three key modules that you test before the final agreement. The schedule is set from your requirements, and the code is transferred on full payment.