Product Process & Schedule Design

Transcription

1 Product Process & Schedule Design

2 Relationship between product, process, and schedule design and facilities planning Product designers Process planner Production Planner Facilities planner

3 Before any facility plan can be generated, the following questions should be addressed 1. What is to be produced? 2. How are the products to be produced? 3. When are the products to be produced? 4. How much of each product will be produced? 5. For how long will the products be produced? 6. Where are the products to be produced?

4 Relationship between product, process, and schedule design and facilities planning Product design Facilities design Process design schedule design Figure 2.1 Relationship between product, process, and schedule (PP&S) design facilities planning.

5 Facility planning functions relationship Links between components: Product Change in the design of a product. Introducing a new product. A significant increase in demand. Process: Chang in the design of a process. Replacement of a machine. Adaptation of new standards.

6 Facility planning functions relationship Links between components: Scheduling: Bottlenecks Delay and idle time. Excessive temporary storage Obstacles to material flow. High ratio of material handling time/production time

7 Product, Process & Scheduling Design Interaction 1 Product Design 2 Process Design

8 Product, Process & Scheduling Design Interaction 3 Scheduling Design 4 Facilities Design

9 1. Product Design Steps Customer Needs Market Surveys, Benchmarking QFD, HOQ. etc. Product Designer Exploded Assembly Drawing or Photograph Can be prepared and analyzed by CAD Component Design Detailed component part drawing Can be prepared and analyzed by CAD

10 Product Design Product design involves The determination of which products are to be produced The detailed design of individual products. Decisions regarding the products to be produced are generally made by top management based on input from marketing, manufacturing, and finance concerning projected economic performance.

11 Product Design Product must meet customer needs, this challenge can be achieved by designers using QFD and benchmarking. Either Exploded Assembly Drawing or Photograph can be used to show the parts properly oriented. Detailed component part drawing are needed for each component part. Drawings can be prepared and analyzed by CAD system.

12 Product Design involves: Quality Function Deployment (QFD) House of quality (HOQ) Benchmarking Design for Manufacturing and Assembly (DFMA) Prototyping (The first testing pattern) Exploded Assembly Drawing Photography CAD drawing

13 Figure 2.2 Exploded assembly drawing

14 Exploded Assembly Drawing materials in an airplane

15 Exploded Assembly Drawing

16 Figure 2.3 Exploded Assembly Photography

17 Figure 2.4 Component part drawing of a plunger

18 2. Process Design Steps Identifying Required Processes Make or Buy Decision & Parts list. Bill of Materials (BOM) & Product Structure. Selecting Required Processes Route sheet. Sequencing Required Processes Assembly Chart, Operation Process chart & Precedence Diagram.

19 Process Design How the product is going to be produced, on which machine, make or buy decision, how long it will take to perform the operation. Basically process design consists of 3 stages: 1. Identifying the required process make-or-buy decision part list bill of materials

20 Process Design 2. selecting the required processes process selection procedure route sheet 3. sequencing the required processes assembly chart operation process chart Precedence diagram

21 Process selection & Design process

22 Make or Buy Decision Process Figure 3.6 The make-or-buy decision process.

23 Process Identification Define elemental operations Step 1 Identify alternative processes for each operation Step 2 Analyze alternative processes Step 3 Standardize processes Step 4 Evaluate alternative processes Step 5 Select processes Step 6 Computer Aided Process Planning (CAPP) - Variant -Generative Figure 3.10 Process selection procedure

24 After Make or Buy decision After the make or buy decisions have been made, a list of items to be made and the items to be purchased will be determined. The listing often takes the form of a parts list or a bill of materials. A parts list includes at least the following 1. Part numbers 2. Part name 3. Number of parts per product 4. Drawing

25 Process Design A part list 1) part number 2) part name 3) number of parts 4) drawing number 5) material 6) size 7) quantity 8) make or buy

26 Figure 3.8 Bill of martials for an air flow regulator Level I: subassemblies and components that feed directly into level

27 Figure 3.9 Bill of materials for an air flow regulator

28 Selecting the Required Processes After determining in house parts, decisions are needed as to how the products will be made: - previous experiences - related requirements - available equipment - production rates - future expectations. Outputs are processes, equipment, and raw materials required for the inhouse production of products, also called a route sheet.

29 Route sheet The outputs from the process selection procedure are the processes, equipment, and raw materials required for in-house production of products. Output is generally given in the form of a rout sheet. It lists, in addition to part information, the related operations for each make component.

30 Figure 3.11 Route sheet for one component of the air flow regulator

31 Sequencing the Required Process The method of assembling a product is accomplished by the assembly chart. Assembly chart shows the sequence of operations in putting the product together. The easiest method of constructing an assembly chart is to begin with the completed product and trace the product disassembly back to its basic components.

32 Assembly Chart The easiest way of constructing an assembly chart is to begin with the completed product and to trace the product disassembly back to its basic components How to construct it? Figure 3.12 Assembly chart for an air flow regulator

33 Sequencing the Required Process Although route sheets provide information on production methods and assembly charts indicate how components are combined, neither provides an overall understanding of the flow within the facility. This is accomplished with the operation process chart.

34 To provide an overview of the flow within the facility we impose the rout sheet on the assembly chart. The resulting chart is referred to as an operation process chart. How to construct it? Operation process chart analog model of overall production process

35 Sequencing the Required Process A second viewpoint (from graph and network theory) is to interpret the charts as network representations, or more accurately, tree representations of a production process. A variation of the network viewpoint is to treat the assembly chart and the operations process chart as special cases of a more general graphical model, the precedence diagram.

36 Precedence diagram A network representation of all processes need to executed successively. The diagram can be of significant benefit to the facilities planner. It establishes the precedence relationships that must be maintained in manufacturing and assembling a product. Figure 3.14 Precedence diagram for an air flow regulator

37 3. Scheduling Design Steps Marketing Information Quantitative Information such as volume, trend, and predictability of future demand for various products Qualitative information Process Requirements Calculation of production requirements Calculations with rework Reject allowance problem Estimation the number of machines required

38 Marketing Information - Quantitative As a minimum, the market information needed for facilities planning is given in the table.

39 Marketing Information - Quantitative Ideally, information of the type shown in this table would be provided. If such information is available, a facilities plan can be developed for each demand state, and a facility designed with sufficient flexibility to meet the yearly fluctuations in product mix.

40 Marketing Information - Qualitative The qualitative information listed in this table shall be obtained as well. This information may provide valuable insight to facilities planner.

41 Marketing Information Pareto s Diagram The figure above suggests that the facilities plan should consist of a mass production area for the 15% of high volume items and a job shop arrangement for the remaining 85% of the product mix. Pareto law dose not apply for the figure below.

42 Process Requirements Example 2.1: A product has a market estimate of 97,000 components and requires three processing steps (turning, milling, and drilling) having scrap estimates of P1 = 0.04, P2 = 0.01, and P3 = , , ,

43 Process Requirements Example 2.2: The end product requirement is 100,000 pieces, Assume that the defective rate in (decimal) are d1= 0.03, d2 = 0.40, and d3 = 0.02 Solution: Applying this equation, The initial input required is 103,280

44 4. Facilities Design Steps QC Tools Some quality Tools such as Pareto Chart can be used Deming Wheel Deming BDCA Cycle of continuous improvement can be very useful (Plan-Do-Check-Act) Seven Management & Planning Tools Affinity diagram, Interrelation Diagraph, Tree Diagram, Matrix Diagram, Contingency Diagram, Activity Network Diagram, and Prioritization Matrix.

45 7 management and planning tools The seven management and planning tools are 1. The affinity diagram, 2. The interrelationship digraph, 3. The tree diagram, 4. The matrix diagram, 5. The contingency diagram, 6. The activity network diagram, and 7. The prioritization matrix.

46 Affinity Diagram The affinity diagram is used to gather verbal data, such as ideas and issues, and organize it into groupings. Suppose we are interested in generating ideas for reducing manufacturing lead time. In a brainstorming session, the issues are written down on "post-it notes and grouped on a board or wall. Each group then receives a heading. An affinity diagram for reducing manufacturing lead time is presented in the following figure.

47 Affinity Diagram Procedure: 1. State the issue in a full sentence. 2. Brainstorm using short sentences on self-adhesive notes. 3. Post them for the team to see. 4. Sort ideas into logical groups. 5. Create concise descriptive headings for each group.

48 Affinity Diagram Affinity diagram example for reducing manufacturing lead time

49 Interrelation Diagraph The interrelationship digraph is used to map the logical links among related items, trying to identify which items impact others the most. The term digraph is employed because the graph uses directed arcs

50 Interrelation Diagraph Suppose we want to study the relationship between the items in previous figure under facilities design. The interrelationships are presented in this figure. Note that this graph helps us understand the logical sequence of steps for the facilities design

51 Tree Diagram Maps out the paths and tasks necessary to complete a specific project or reach a specified goal. Benefits: Encourages team members to think creatively. Makes large projects manageable. Generates a problem-solving atmosphere.

52 Tree Diagram Procedure: 1. Choose an action-oriented objective statement from the interrelationship diagram, affinity diagram, brainstorming, team mission statement. 2. Using brainstorming, choose the major headings. 3. Generate the next level by analyzing the major headings. Repeat this question at each level.

53 Tree Diagram Tree diagram for the formation of product families

54 Matrix Diagram The matrix diagram organizes information such as characteristics, functions, and tasks into sets of items to be compared.

55 Contingency Diagram The contingency diagram, formally known as process decision program chart, maps conceivable events and contingencies that might occur during implementation.it is particularly useful when the project being planned consists of unfamiliar tasks. The benefit of preventing or responding effectively to contingencies makes it worth while to look at these possibilities during the planning phase. This figure shows an example of possible contingencies during an earthquake.

56 Activity Network Diagram The activity network diagram is used to develop a work schedule for the facilities design effort. This diagram is synonymous to the critical path method (CPM) graph. It can also be replaced by a Gantt chart and if a range is defined for the duration of each activity, the Program Evaluation and Review Technique (PERT) chart can also be used. An example of an activity network diagram for a production line expansion is illustrated in this figure

57 Activity Network Diagram The important message is that a well thought out time table is needed to understand the length of the facilities design project. This timetable can be developed after the actions on the tree diagram have been evaluated with the prioritization matrix. Teams activities can also be planned as shown in this typical weekly work schedule.

58 Prioritization Matrix In developing facilities design alternatives it is important to consider: Layout characteristics Material handling requirements Unit load implied Storage strategies Overall building impact The figure shows prioritization matrix for the Evaluation of Facilities Design alternatives.

59 Prioritization Matrix The prioritization matrix can be used to judge the relative importance of each criterion as compared to each other. Table 2.12 presents the prioritization of the criteria for the facilities design example. The criteria are labeled to help in building a table with weights. This figure shows the Prioritization Matrix for Layout Alternatives Based on WIP Levels

60 Summary Logical application sequence of the seven management and planning tools is shown in this figure.

61 Summary This figure shows how the seven management and planning tools facilitate the planning of a facilities design project