Manufacturing Supply Chain - Medical Device Design: Innovation from Concept to Market - page 265

Table 10.4: Some Common Terms Used by Supply Chain

Name Description Batch Sizes

Just in time (JIT) Goods are delivered exactly when

needed and little/no stock held on
shelves.

Large, good for regular
consumables

Historically a card-based system
that “pulls” stock as it becomes
depleted.

KANBAN Any

Batch size The number of items in any

one order.

Any

Medium to large batch sizes

Materials resource planning
(MRP)

A software-based system to
control inventory and production
planning.

Literally only one (or maybe two)
items are made. Each batch is
different to the last.

Very small

One-off production

Bill of materials (BOM) A complete list of components,

assemblies, and subassemblies for
your device.

All

Lead time The time it takes for the

component to arrive after it has
been ordered.

All

Constant work-in-progress
(ConWiP)

The flow of product is continual
with equal size batches arriving at
equal intervals.

All, but sales must be highly
predictable and repetitive. This
is for a product that is well
established and has significant
market share.

different manufacturing methods become more effective. For example for small batches you
may obtain a polymer-based component by machining it directly from a block: however,
as batch sizes increase this method of production may become costly and you may wish to
change to injection molding. All of this needs planning, and you will be unable to solve this
issue overnight. So the message here is plan well in advance and secure your short-term,
medium-term, and long-term suppliers well in advance. If you do not do this your purchasing
department will grow to hate you.

10.4.1 Supply Chain Glossary
Table 10.4 illustrates some common manufacturing terms you may meet when discussing
procurement with your supply chain.

10.4.2 Costing
Costing is an art. Unless you have spent your life costing the manufacture of components,
this is a lost cause. However, most CAD packages come with an estimation algorithm built