Manufacturing Systems at the
enterprise level
What is called manufacturing system ?
 System: a set of components that are connected in a rational way to
perform functions.
 Manufacturing systems are a system to make products. So making a
product is the function of a manufacturing system.
 Resources are needed for a system to perform a function.
 Environments are needed for a system to perform a function.
 Manufacturing firms are a profit-based organization, so they have to
consider the cost of making a product and the return they can get from
selling their products
Manufacturing Systems: three levels
Logical (for each manufacturing firm or entity or system):
Firm level
Shop floor level
Machine level
All our previous discussions are at the
machine level. A machine is considered as a
system that processes materials to make a
product
Manufacturing Systems: three levels
Physical (for each manufacturing firm or entity or system):
Firm level
Shop floor level
Machine level
A manufacturing system can be one
person with one machine. In this case, the
three levels are flattened into one but this
one physical entity has three logical
functions.
Firm view of manufacturing systems
Finance or
money
Environment
Materials
Capital equipment
Production tooling
Energy
Manufacturing
Systems along
with its
process, e.g.,
business of
repairing
Sustainability
Resilience
Labor
Health& Safety
Completed
product
Scraps
or
wastes
Classification of manufacturing systems (firm level)
(1) project,
(2) job shop,
(3) repetitive,
(4) line and
(5) continuous
Manufacturing systems at the enterprise level
Project:
 One of a kind (such as ship and nuclear power plant)
 Complex
 Site building (production tools must get to the site)
Job Shop:
 Low volume and production quantities, called lot sizes
 Not site building (traditional workshop)
Manufacturing systems at the enterprise level
Process-based
layout
Product-based
layout
Repetitive:

Orders for repeat business approach 100%.
 Blanket contracts with customers for multiple years
occur frequently.
 Moderately high volume with lot sizes varying over
wide range.
 Fixed routing for products.
Remark: The system or plant is laid down in either processbased or product-based flow manner.
Manufacturing systems at the enterprise level
Line:
 Delivery time (often called lead time) required by the customer
is often shorter than the total time it takes to build the product.
 Product has many different models and options.
 An inventory of subassemblies is normally present.
Examples: Car and Truck.
System is laid down as a product-based flow manner.
Manufacturing systems at the enterprise level
Continuous:
 Manufacturing lead time is greater than the lead time
quoted to the customer.
 Product demand is predicable.
 Product inventory is held.
 Volume is high.
 Products have few options.
Examples: Chemical components.
System is laid down in a product-based flow manner.
Characteristics of manufacturing Systems
Production strategy classification
To deals with how to market the product
Criteria for classification:

customer lead time (CLD) and

manufacturing lead time (MLD)
Engineer to order:
Product is either in the first stage of the life-cycle curve or
a complex product with a unique design produced in
single-digit quantities.
Example: construction industry (bridge, etc.)
Customer is willing to accept long MLD - permitting this
strategy
Make to order:
All the engineering and design works are completed and
the production process is proven.
Example: new residential homes.
The customer’s demand is unpredictable.
Assemble to order:
 Primary reason of this strategy: MLD > CLD.
 Order is statistically predicable.
Examples; automobiles, personal computers
This strategy is especially adopted in the
manufacturing type
line
Make to stock:
- Reasons for this strategy: (1) CLD < MLD (2) product
configuration has few options so that the demand
can be predicated accurately.
- Product parts are often stocked in distribution
warehouses located in major population centers.
Production strategy versus MLD:
Maximal MLD
:
ETO
Minimal MLD
:
MTS
Manufacturing systems at the enterprise level
It is important to be aware that the
production strategy can be changed with
the product evolution. MTO may not suit
the product which has a high component of
R&D; however MTO may be applied when
that product goes to maturity.
Enterprise organization
Architecture
Aim: examine different function units and their
communications
Manufacturing organization see Figure 1.6 where
boxes represent different function units and
arrowhead lines indicate the communications.
Figure 1.6
Product and Process Definition (Figure 1.7)
Finance and management
Sales and
Marketing
Product
Product
Design
design
Production
Production
engineering
Engineering
Engineering
release
Manufacturing
planning and
control
Quality
Quality
Manufacturing planning and control
(See Figure 1.8)
Manufacture process planning
determine the type of machines required to process the
parts and the production sequence, called the routing, to
be used
Production planning -> scheduling (time factors
included)
Manufacturing
Planning and
Control (MPC)
MPC versus
others
Production sequence
Manufacturing systems at the enterprise level