Introduction, Performance, Design (JS, Cell, Line, Assembly)

PRODUCTION SYSTEMS

PRODUCTS LIFE CYCLE

• INTRODUCTION
• Critical design and development phase
• Frequent changes in product and process design
• Short production runs
• High production costs
• Attention to quality
• GROWTH
• Forecasting needed
• Competitive product improvements
• Increase of capacity
• Enhanced distribution
• MATURITY
• Standardization of products (no changes)
• High capacity, long production runs
• Cost cutting
• Increasing stability of processes
• DECLINE
• Overcapacity - Reduce it
• Try to eliminate items not retaining good margins

PRODUCTION

It is the sum of the processes and methods used to transform tangible inputs (raw materials, subassemblies...) and intangible inputs (information, knowledge...) into goods or services / output that are suitable for use or have exchange value.

PRODUCTION SYSTEM

A production system is the combination of the production processes and all the management subsystems contributing to make the transformations (production process).

Row Material

Energy

Information

INDUSTRIAL PRODUCTION SYSTEM

• Equipment
• Personnel
• Information
• Know-how

PRODUCT

PRODUCTION PROCESS

Production process is the transformation of making resources (input) into finished products or goods (output) taking place in a productive system.

Technologically speaking, it is the application of physical and chemical processes to alter geometry, properties, or appearance of a given starting material to produce products.

Economically speaking, it is the transformation of materials into items of greater value by means of one or more operations.

DISCRETE PART PRODUCTION SYSTEM (each part is distinct)

It can be:

• CONTINUOUS GOOD PRODUCTION (never stop, for fluids, powders)

DESIGN -> INDUSTRIALIZATION -> PRODUCTION

• Engineering Drawings
• Bill of materials BOM
• Route Sheet (Technological cycle)
• Processing and assembly drawings

BOM

Hierarchical and structural depiction of all the objects (sub-assemblies, compounds, raw materials) composing a product (parents, items, children items).

ASSEMBLY DRAWING

They show exploded views of products and how to assemble them.

ROUTE SHEET

It contains the list of operations, with resources and time required.

WORK ORDER

It contains instructions to produce a given quantity (where, when, how much).

Production processes are multistage processes, it means that a sequence of operations are required to realize the process that allows to obtain a product from a raw material.

The set of data that describes the sequence of such operations is called TECHNOLOGICAL CYCLE of ROUTING.

• ○ Operate
• ▽ Store
• □ Inspect
• □ Wait
• → Transfer

ATO - ASSEMBLE TO ORDER

• Customer lead time less than manufacturing lead time.
• Some forecast must be done.
• Various options can be selected.

MTS - MAKE TO STOCK

• Useful when delivery response time is a key competitive factor. It allows to schedule production in advance.
• Quick delivery (customer lead time less than manufacturing lead time that is minimized).
• Products have few options but a good demand.

HAMBURGERS

MC = make to stock production, very fast in delivery but no selection

BK = they wait for the order to assemble, make it your own way

• As soon as they change and start assembling the meat needed.
• Hamburger keeps it on the rack.

WENDY'S

• Keep on cooking. If you show up and eat an hamburger, okay; if not they use that meat to do chili (other product).
• This is make to order more than ordered.

NEW MC - They wanted to renew the technology in designing a new process

• During the WIP, they keep the meat warm to make it seem like it had just been cooked
• BUT they went back on the previous process (not for technology)

Quality of view is higher

• Reputation of old one higher with respect to target customer.
• Responsiveness of new one low, 2 minutes are too much queue as they waited with simmering chicken.

=> They came back to the old one

ACCURACY (OR PRECISION)

It evaluates the quality of the order preparation system (wrong items sent). The delivery mistakes can be of packaging, items, batches.

PHYSICAL

• Nº of mistakes at the delivery
• Nº of orders managed
• Nº of returns due to delivery mistakes

ECONOMIC

• Cost of the penalty for inaccurate delivery
• Cost of management and accounting activities duplication (reducing things, re-transport them)

COMPLETENESS

It evaluates the reduction in the level of service perceived by customers in terms of speediness of order fulfillment (not a wrong item but a missing one). If you are not accurate, you cannot be complete.

PHYSICAL

• Nº of order rows fulfilled with 1^st delivery
• Nº of total rows
• Average Nº of deliveries for each order

ECONOMIC

• Value of order rows fulfilled at 1^st delivery
• Total value of rows
• Cost of fractional deliveries

AVAILABILITY (STOCK OUT) MTS

It takes into account the phenomena of stock out.

PHYSICAL

• Nº of items in stock out
• Nº of total items
• Nº of order filled
• Nº of total orders
• Nº of order lines filled
• Nº of total order lines
• Nº of codes filled
• Nº of codes required

ECONOMIC

• Cost of the lost margin due to stock out (when not recoverable)
• Cost of the penalty for delayed delivery (if customer is willing to wait - back log present; reshopping)
• Cost of the loss of reputation

STOCK OUT PERSISTENCY (UNAVAILABILITY)

It measures the going on of the stock-out issue.

PHYSICAL

• Average time of delivery of the orders delivered not "off-the-shelf"
• Nº of periods in stockout
• Nº of total periods

YIELD Y = Good Pieces / Total Produced Units

SATURATION S = Machining Time / Actual Production Time

In real life actual performances are often lower than the expected.

PRODUCTIVITY MEASURES

PRODUCTIVITY = OUTPUT / INPUT = Production Volume / Level of use of a certain production factor

• Material Productivity
• Machine Productivity
• Workforce Productivity

These measurements can have different references:

• a single machine - a group of machines
• steps of the production process - entire production system

And different ingredients:

• Partial measure OUTPUT SING. INPUT
• Multifactor measure OUTPUT MULTI INPUT
• Total measure OUTPUT ALL INPUTS

To make a diagnosis, it’s not so useful to aggregate the productivity measures.

More useful indications derive from the decomposition of PRODUCTIVITY P

PRODUCTIVITY = UTILISATION U * EFFICIENCY η

Output = production in hours that, according to standard, are necessary to produce a specific object, including the setup time.

Input = it changes according to the productive factors considered (machine, material, workforce).