Loading

Routings and Work Centres

A routing is the list of operations that make an item: in what order, at which work centre, with how many setup minutes per batch and run minutes per unit. A work centre is where the work is done, with a labour and an overhead rate per hour. Together they give each item a conversion cost (labour and overhead), and on a work order they are the operations people report against.

Where to find it

Architect Panel → ERP - Operations:

  • Production — the console: the Work centres tab
  • Structures — the console: the Routing card under each structure

Admin Panel → Inventory & Production:

  • Production — work centres, for planners and production staff
  • Structures — routings, for planners

The underlying datastores are Work Centres and Routing Operations under Data → Datastores.

Setting up work centres

  1. Open Production, choose the company and go to Work centres.
  2. Click New work centre.
  3. Enter a Code (letters, digits, dots, dashes or underscores) and Name.
  4. Enter Labour / hour and Overhead / hour, Capacity (h/day) and Efficiency % (run time is divided by this, so 80% makes each run take longer).
  5. Leave In use (new routings can choose it) ticked and click Create work centre.

Only an architect can tick Shared by every company, and only when creating it. The list shows each centre's rates, capacity, efficiency and Open load: the hours still to do on operations of open work orders, also in days at its capacity, with a busy pill above five days. Capacity is for information only; nothing schedules work orders against it.

Adding a routing to a structure

  1. Open Structures and open a saved bill of materials or recipe. Kits have no routing.
  2. In the Routing card below the components, click Add an operation. Operations are numbered 10, 20, 30.
  3. For each, enter a Description, choose the Work centre, and enter Setup min (batch) and Run min (unit). Leave Labour rate and Overhead rate blank to use the centre's, or enter an override.
  4. Set the Costing lot size: the batch the setup time is spread over. 0 uses the item's reorder quantity.
  5. Click Save routing.

The card then shows the Conversion cost of one unit: minutes per unit, labour and overhead per operation. Roll up the cost to make it the item's standard (see Production & Costing). A new revision of the structure copies its routing.

How the cost is worked out

Minutes per unit for an operation are the setup minutes divided by the costing lot, plus the run minutes adjusted for the centre's efficiency. Labour is those minutes in hours times the labour rate, and overhead the same at the overhead rate. A work order takes a snapshot of the routing when it is created, charging the full setup once for the order's quantity.

What goes wrong

  • "Choose a work centre." or "Work centre X is switched off.": pick an active centre. A group-wide structure needs a centre every company shares.
  • "An operation takes some time: enter setup or run minutes."
  • "Operation N at C has no labour or overhead rate, so it costs nothing.": set the rates on the centre.
  • "No work centres yet" on the Routing card: create them on the Production console first.
  • "A group-wide structure's routing is changed by an administrator."

Worked example

A pump assembly has two operations: 10 Assemble at centre ASSY (labour 32.00, overhead 18.00 an hour, 100% efficiency) with 30 minutes setup and 12 minutes run, and 20 Test at centre TEST (28.00 and 12.00) with 0 setup and 6 minutes run. With a costing lot of 50, Assemble is 12.6 minutes a unit and Test 6, so conversion is 9.52 labour (6.72 + 2.80) and 4.98 overhead (3.78 + 1.20) per pump. The planner rolls up the cost and sets it as the standard.

Recommendations

  • Keep work centres few and real: one per group of machines or people that share a rate.
  • Use achieved times, measured from operation reports, not estimates.
  • Set a realistic costing lot, or setup cost is spread too thinly or too thickly.
  • Roll up costs after changing a routing, so the standard matches.