Function Modeling

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UNIVERSITY OF EXETER

Function ModelingIDEF0

Manufacturing Systems (ECMM111) as part of ECMM120

ABSTRACT: Information given about different functions within an Order Handling ManufacturingSystem (OHMS) were translated into an IDEFO model.

Augustine Owusu


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Table of Contents

Section 1: Introduction .................................................................................................................................. 2

Section 2: Theory .......................................................................................................................................... 2

Section 3: Methodology ................................................................................................................................ 4

Section 4: Results .......................................................................................................................................... 4

4.1. Node Index of the OHMS .................................................................................................................. 4

4.2. IDEF0 Models for the OHMS............................................................................................................ 5

References ................................................................................................................................................... 13

Table of Figures

Figure 1 - Semantics of IDEF0........................................................................................................................ 3

Figure 2 - IDEF0 model for A0 ....................................................................................................................... 5

Figure 3 - IDEF0 Model for A1 ....................................................................................................................... 6

Figure 4- IDEF0 Model for A2 ........................................................................................................................ 6

Figure 5 - IDEF0 model for A22 ..................................................................................................................... 7

Figure 6 - IDEF0 model for A3 ....................................................................................................................... 8

Figure 7 - IDEF0 model for A32 ..................................................................................................................... 9

Figure 8 - A4 ................................................................................................................................................ 10

Figure 9 - A42 .............................................................................................................................................. 11


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Section 1: IntroductionThis exercise is intended to show understanding of how to represent information about a system

of functions as a schematic of the system using IDEF0. A Just-in-time/Mass Customisation

system (OHMS) was given. The information which was given about this entire system was put

into IDEF0 format.

Section 2: TheoryEngineering business entities can be made up of several functions or departments, between

which there are flows of information, finance and materials. These three kinds of flow can often

have complicated flow networks within the system.

There needs to be a common methodology for representing such a system. This methodology

should achieve the following:

Providing a format in which complicated networks of function within a system would

appear simple (i.e. schematic)

Consistency in representation

IDEF0 achieves such objectives. IDEF0 is a standardized way modeling the schematic of a

system of functions or processes. It is particularly useful to visualize complex systems, which are

made up of several inter-linked processes. IDEF0 represents each function as an entity

represented by a rectangle. All parameters or items relating to a particular process or function are

categorized into inputs, controls, outputs, calls and mechanisms. The processes or functions are

then linked together and where necessary, the procedure is repeated for some processes or

functions for more details about them.


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Figure 1 - Semantics of IDEF0

Figure 1 above gives an overview of the basic components of an IDEF0 model. The Process

Name is usually expressed as a verb or command phrase.

The Input refers to anything that is consumed or transformed by the process.

The Control refers to anything that guides or constrains the process.

The Output refers to any result of the process.

The Call is any information that is produced during the process in order to support other

processes or functions. The Callis distinguished component of the IDEF0 as it may fit the

definition of an output, however it may also fits the opposite definition of a mechanism. Instead

of a Call being a supporting means of carrying out the function (as the definition of a mechanism

suggests), a Call is rather generated by the function in support of other functions.

The Mechanism refers to the means by which the process produces the output.

So far, the basic components of an IDEF0 model have been outlined. Due to the instructions which were

given on the question paper, (i.e. to construct IDEF0 models in terms of inputs, controls, outputs and

mechanisms) the Call component shall not be included in this exercise.


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Section 3: MethodologyA node index of the Order Handling Manufacturing System (OHMS) was summarized based on

the information given on the question sheet.

Using the node index and further information from the question sheet, IDEF0 models were

constructed for the OHMS with Microsoft Visio software.

Section 4: Results

4.1. Node Index of the OHMS

A0 Make to customer order

A1 Formulate Production Plan

A11 Sale and Contract

A12

Plan Production ProgrammeA2 Design and Develop Product to Order

A21 Control Design and Development Process

A22 Develop Prototype

A221 Prepare Advanced Drawing

A222 Make and Test Prototype

A223 Prepare Final Drawing and Parts List

A3 Gather production resources

A31 Plan Materials and Capacity Requirements

A32 Gather Resources

A321

Acquire Production ResourcesA322 Acquire Bought-out Items

A4 Produce product

A41 Control Production Operation

A42 Carry out Production Operation

A421 Produce Parts

A422 Produce Sub-assemblies

A423 Produce Final Assembly

A424 Test Final Assembly


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4.2. IDEF0 Models for the OHMSFigure 2 - IDEF0 model for A0

Figure 2 above shows the IDEF0 model for the overview of an OHMS operation. Contact

between the OHMS and the customer is made throught the A1 function. This involves incoming

customer orders and enquiries. The A1 function deliver promises. Also, there is flow of cost

information from all the other functions (i.e. A2, A3 and A4) as a control to A1. Thisinformation is to guide A1 to output quotations and proposals.

A2 is responsible for design and development of the ordered product. It uses customer

requirements and delivery promises as control parameters to output technical data from designs

as well as prototype testing results. The prototype testing results are fed back into A2 as a control

parameter. This is because information from failed prototype tests should set design constraints

for A2 or guide A2 to develop better designs. Also there is an output of Prototype testing results

from A2 because, for legal reasons the prototype testing may need to be documented.

Function A3 is responsible for purchasing. It receives a control signal from A1, when deliverypromises are made to the customer. A3 then gathers the resources which are necessary for

production. A3 outputs the bought-out items.

Function A4 receives bought-out items as an input for production of the customers order. Its

controls are the technical data from the product design from A2, as well as delivery promises

made to the customer from A1, in order to guide production timing.


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Figure 3 - IDEF0 Model for A1

Figure 4- IDEF0 Model for A2


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Figure 5 - IDEF0 model for A22


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Figure 8 - A4


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Figure 9 - A42


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ReferencesKnowledge Based Systems, Inc. (1993, December 21).Announcing the Standard for INTEGRATED

DEFINITION FOR FUNCTION MODELING (IDEF0).

Knowledge Based Systems, Inc. (2012). Official website for Integrated Definition Methods (IDEF).

Retrieved from http://www.idef.com/IDEF0.htm

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