Bill of material. A bill of material (BOM) represents the structural links between finished products, intermediate items, components and raw materials

Transcription

1 Bill of material A bill of material (BOM) represents the structural links between finished products, intermediate items, components and raw materials FP A B C x y z 1

2 Manufacturing cycle Manufacturing cycle may be expressed using different degrees of detail For management purposes, it represents significant manufacturing operations in relation to a specific level of the bill of material 2

3 Relationship between bill of material and manufacturing cycles A X a f B C k j D 3

4 The Production Planning and Control (PPC) process Hierarchical decomposition in phases with different: timeframes objectives constraints detail of the production plan 4

5 PPC process phases Demand management Aggregate planning Master production scheduling (MPS) Inventory management and material requirements planning Scheduling Production control 5

6 Sales production interaction The interaction between the sales and production areas works both ways, as the sales department must: forecast demand, to provide input for production respond to customer requests, using information provided by production 6

7 Forecasting demand Forecasting errors may be reduced by: making aggregate forecasts (e.g. product families) making detailed forecasts close to the current time Consequently: forecasts for more distant periods should be as aggregate as possible detailed forecasts (individual items) should refer to periods close to the current time 7

8 Forms of product aggregation Product families (groups of items with the same characteristics) Average products (virtual, statisticallysignificant product) Basic products, personalised after the order according to customer specifications 8

9 Demand forecast techniques (1) Time-series models: are based on the assumption that the future is a function of the past; they look at what has happened over a period of time and use a series of past data to make a forecast Requirements: availability of adequate series of past data stability of the causes on which past demand was based 9

10 Demand forecast techniques (2) Regression models: use past data to allow identification of relationships between demand and some of the independent variables that influence it Requirements: valid hypotheses of correlation between demand and independent variables forecasts of the future values of independent variables must be more reliable than direct demand forecasts 10

11 Responding to customer requests: information requirements (1) MTS: access to information on stocks of finished products access to information on the future availability of finished products (ATP, Available To Promise) ATO: access to information on stocks of modules access to information on the future availability of modules (ATP) knowledge of assembly lead times product configuration management 11

12 Responding to customer requests: information requirements (2) MTO: access to information on the future availability of production capacity knowledge of production (manufacturing + assembly) lead times PTO: access to information on the future availability of production capacity knowledge of production lead times knowledge of purchasing lead times 12

13 Responding to customer requests: information requirements (3) ETO: estimate of the future availability of resources estimate of lead times of the various activities and their precedence relationships estimate of costs 13

14 Configuration bill Represents the components that may be chosen depending on customer requests (usually in the context of ATO) Computer Keyboard.. Keyboard 1 Keyboard 2 Keyboard 3 14

15 Product configuration In the context of ATO there is the problem of configuring the product based on the customer requests The product configuration manager is a tool that allows us to select the elements of the configuration bill using different logics 15

16 Product configuration: example Computer A Disk Optional Keyboard CPU 80 GB External disk Keyboard GB DVD Keyboard 2 Keyboard 3 At least one Optional One and only one Fixed 16