Facilities layout and arrangement Quantitative method in facilities

• Facilities layout and arrangement • Quantitative method in facilities planning

Definition 1. Location • Space where the facilities; building; equipment & tools are placed 2. Layout • The physical arrangements of departments, workstations or machines stock-holding point within a manufacturing facility • The space for material movement, storage, labor & staff, supporting activity & services and tools

Design of Facilities Layout Aims To minimize total cost Optimum Quality Increasing the efficiency of work energy utilization, space, equipment and energy sources Preparation of basic facilities, safety precaution and comfortable level for workers Controlling the project cost Build up variety on planning Decrease inventory level Reducing hazards to employees

Design of Facilities Layout Issues to be considered 1. New Facilities • New technologies / new product 2. Design replacement • Replacement of facilities design and equipment layout 3. Cost efficiencies • Find new layout that increasing the production of the product without exceeding initial setup cost 4. Uncomfortable work situation & repetition of accident • Needs replacement/redesign of facilities layout

Design of Facilities Layout Types of Layout i. iii. iv. Production Line Fixed Position Layout Process Layout (Functional) Group / Cellular layout

Characteristics of a Good Layout • • • Reduces bottlenecks in moving people or material. Minimizes materials-handling costs. Reduces hazards to personnel. Utilizes labor efficiently. Increases morale. Utilizes available space effectively and efficiently. Provides flexibility. Provides ease of supervision. Facilitates coordination and face-to-face communication where appropriate.

Line Layout • Plant arrangement to facilitate material processing in the same order. • Suitable for mass production system • Need to categorise operations to ensure equal processing time at all work stations (line balancing) • Best for repetitive/continuous production • The product move along in a smooth are continuous flow, resources are arrange around the product

• Unsuitable for machining processes due to inherent differences in processing times. • High level of machine and manpower utilisation. Layout production line

Process (Functional) Layout • Plant grouped according to type of process • Specialisation of skills • Higher machine utilisation • Queues of work • Longer lead times • Flexibility of operation • Low volume and high variety manufacturing

Process (Functional) Layout Grinding Forging Lathe Painting Welding Drills Office Milling L L M M G G D D Foundry G G D D

FIXED POSITION LAYOUT • Product is fixed in place, workers along with their tools & equipment come to product to work on it • Type of product massive one difficult to move • Example ; assembly locomotive, making huge pressure vessel, building dams , ships or aircrafts.

Group/ Cellular Layout • Plant divided into groups or cells. • Individual cells with function to complete a part process of a whole family of parts. • Shift of emphasis from process specialisation (functional layout) to product specialisation. • Used mainly for families of parts. • Mainly focused on Group Technology

Group Technology 1. Definition: GT is a manufacturing philosophy in which similar parts are identified and grouped together to take advantages of their similarities in design and production 1. Processing of each member of a given part family is similar, and this should result in manufacturing efficiencies. 2. Organizing the production equipment into machine cells, where each cells specializes in the production of part families is called Cellular Manufacturing Note: part families are collection of parts that are similar either in geometric shape and size or in the processing steps required in their manufacture

Group Technology 4. Benefits • Promotes standardization of tooling, fixturing and setups • Material handling is reduced because the distances within a machine cell are much shorter than within the entire factory • Process panning and production scheduling are simplified • Setup times are reduced, resulting in lower manufacturing lead times • Reduced WIP • Worker satisfaction improves • High quality work is accomplished

Part Families

Process type layout vs. GT layout

Fixed Position Layout Pros Cons Ø Less material handling Ø High flexibility Ø Workers can prepared all product Ø Responsibility and continuous operation Ø Free Schedule Ø Movement of workers and equipment/tools increase Ø Equipment Duplication Ø Need more skills Ø General maintenance Ø Difficulties and cost of material and machine position Ø Less of tools/equipment utilization

Product Layout Pros Cons Ø Ø Ø Breakdown of one machine, stop production Ø Changing on product cause change of layout Ø Rate of production based on the slowest machine Ø General maintenance Ø High capital because of machine duplication and not full utilize Smooth and logical flow Less production time/unit Less material handling No need high skills Ease of production planning control system Ø Less of space for temporary storage

Process Layout Pros Ø Better on machine utilization Ø High flexibility on distribution of tools and works Ø Lower machine investment Ø Job miscellaneous to improve interest and workers satisfaction Ø Specific maintenance Cons Ø Long flow material and high cost of material handling Ø More on production planning control system Ø More WIP Ø Capacity and space bond to WIP Ø Need more skills Ø Complex to manage with flows crossing each other and moving on irregular and intermittent paths.

Quantitative Methods in Cellular Manufacturing 1. Rank Order Clustering • Grouping parts and Machines by referring to Part-Flow Analysis chart (a tabulation of process and machine code numbers • Apply the method to the part-machine incidence matrix • Works by reducing the part-machine incident matrix to a set of diagonal blocks that represent part families and associated machine groups 2. Hollier Method • Used when there is the part need to be processed by more than one machine group • Used data contained in From/To charts • Intended to place the machines in an order that maximizes the proportion of in-sequence moves within the cell

Rank Order Clustering Apply the rank order clustering technique to the part-machine incident matrix in the following table to identify logical part families and machine groups. Parts are identified by letters, and machine are identified numerically Machines A 1 2 3 4 5 6 7 B C D 1 E F G 1 1 1 H I 1 1 1 1

Rank Order Clustering Step 1 - First Iteration (Part- Machine incidence Matrix) 1 Binary Value 28 27 26 25 24 23 22 21 20 2 3 Decimal Equivalent Rank 290 17 81 136 258 65 140 1 7 5 4 2 6 3 Parts Machines A 1 2 3 4 5 6 7 B C D 1 E F G 1 1 1 H I 1 1 1 1

Step 2 – Second Iteration Machines 4 6 7 A Parts B C D E F 1 1 1 5 1 7 1 4 1 3 1 6 1 2 Decimal 96 24 6 64 Equivalent Rank 1 4 8 3 G H I 1 1 1 1 5 24 16 96 1 1 1 7 9 5 7 6 2 Binary Values 26 25 24 23 22 21 20 5

Solution Parts Machines A H D 1 5 7 4 3 6 2 1 1 1 B F G 1 1 1 I C E 1 1 1 1

Quiz 1. Apply the rank order clustering technique to the part machine incident matrix in the table that follows to identify logical part families and machine groups. Parts are identified by letters, and machines are identified numerically Parts Machines A 1 2 3 4 5 6 7 8 B C D E F G H 1 1 1 1 1

Hollier Method Suppose that four machines, 1, 2, 3 and 4 have been identified as belonging in a GT machine cell. An analysis of 50 parts processed on these machines is shown in the Table below. Additional info: 50 parts enter the machine grouping at machine 3, 20 leave after processing at machine 1, 30 parts leaves after machine 4 To: From: 1 2 3 4 0 30 10 10 5 0 40 0 0 25 15 0 0

i) From and To Sums (1 st Iteration) To: 1 2 3 4 “From” Sums From: 1 2 3 4 “To” sums 0 30 10 10 50 5 0 40 0 45 0 0 0 25 15 0 0 40 30 45 50 10 135

i) Determine the From/To ratio To: 1 2 3 4 “From” Sums From/To ratio From: 1 2 3 4 “To” sums 0 30 10 10 50 5 0 40 0 45 0 0 0 25 15 0 0 40 30 45 50 10 135 0. 6 1 ∞ 0. 25 Machine with high From/To ratio distribute more work to other machines in the cell but receives less work from other machines. Machine with lower From/To ratio receive more work than they distribute

Machines are arranged in order of descending From/To ratio. In case of a tie, machine with higher From value will be placed ahead Machine sequence: 3 2 1 4 Build a network diagram to conceptualize the work flow in the cell?

Performance measures: 1. Percentage of in-sequence move 2. Percentage of bypassing moves 3. Percentage of backtracking moves From the network, 1. No of in-sequence move= 40+30+25=95 2. No of bypassing moves = 10+15=25 3. No of backtracking moves = 5+10=15 4. Total moves = 135

1. Percentage of in-sequence move = 95/135 = 70. 4% 2. Percentage of bypassing moves = 25/135 = 18. 5% 3. Percentage of backtracking moves = 15/135 = 11. 1% Feasible plan layout?

Quiz Four machines used to produce a family of parts are to be arranged into a GT cell. The From/To data for the parts processed by the machines are shown in the table below. By using Hollier method: a) Determine the most logical sequence of machines for this data b) Construct the network diagram for the data c) Compute the percentages of performance measures for the solution d) Develop a feasible layout plan for the cell To: From: 1 2 3 4 0 0 50 0 10 0 0 50 0 0 40 0 20 0