1. Visual Management Cell Kanban System: Cell Scheduling
The XLVI Brazilian Symposium of Operational Research – Salvador, BA - Brazil
SIMULATION ALLIED TO LEAN TOOLS FOR PROCESS IMPROVEMENT OF A METALLURGICAL COMPANY
Authors:
Diogo Nunes Dalosto, Pedro Paulo Balestrassi, Rogério Santana Peruchi, Messias Borges Silva
Institute of Management and Industrial Engineering, Federal University of Itajubá, Minas Gerais, Brazil –UNIFEI
Department of Industrial & Systems Engineering, University of Tennessee, TN – USA
ABSTRACT
Manufacturing companies struggle to meet a fluctuating market demand and deal with issues of price, quality and Lead (cycle) times. Synchronous Flow addresses theses issues by incorporating elements of Six Sigma and Lean Manufacturing principles, as well as simulation to test these improvements. Synchronous manufacturing employs the synchronization between customer orders and work stations. We employ synchronous flow in hydroforming and corrugating area at Fulton Bellows. The result shows substantial improvement in the process.
Visual Management Cell Kanban System: Cell Scheduling
Fig. Current state simulation
Non-value added time: 3480 min.
Value added time: 2.9 min.
INTRODUCTION
Fulton Bellows LCC is dedicated to the manufacturing of bellows with a range of more than 40 different models. Our aim is to improve the flow of material in the process line, specifically in the hydroforming and corrugating area; to decrease the amount of material in process and to speed the process to improve the delivery time of the orders and to be able to increase the productivity of this process.
There are 7 operations, each has a different number of machines. Every bellow has an specific sequence to pass through different machines in each operation. There is no standard procedure to schedule the production and assign the machines due to variability in the processes of different models of bellows that are made and the non-constant demand.
OBJECTIVE
Improve the flow of the material in the process line, specifically in the hydroforming and corrugating area.
Fig. Kanbam System
METHODOLOGY
Assign operators & machines for the first priority
Highest demand is prioritized
After analyzing the production process, two processes were found to be bottlenecks: hydro-forming and trimming operations. We propose cellular manufacturing. To make the cellular production feasible it was organized the principal twenty products in families, so each family has its own system, families then can be arranged in cells and will work with the schedule system.
Celluar manufacturing
In cellular manufacturing, work stations and machines are arranged in a sequence that provides a smooth flow of materials and components through the production process. It offers flexibility to customers the variety they want by grouping similar products into families that can be processed on same equipment in the same sequence. Shorten changeover time between products, reduces unnecessary transportation between stations. We focused on 20 products that have higher demand.
Scheduling
Identify the pieces by the color of the family. After that, prioritize according to the own needs (First in First Out, Highest Demand, Custom Priority).
Fig. Scheduling
FUTURE STATE
Fig. VSM of future state
PROCESS ILLUSTRATION
Trimming
Hydroforming
Fig. Simulation of future state
Fig. Production patterns
A01505A0059 A00753A0017 A00753A0021 A01124A0093
Demand = 20.1%
Set
Perking Press
Trim 14
Restrike & Pierce
Green Press
Deburr
Sanding Belt 1
Restrike and pierce
Deburr
Set
RESULTS
Factors
Actual
Future state
Delta
Production capacity
15,600 pieces
26,400 pieces
69%
Lead-time
3,923 minutes
463 minutes
88,2%
Average utilization
24%
32% 8%
Non - Value added activities
174 horas
7,1 horas
Reduction
95,9%
Fig. Cell- Family A
Set
Air Jig
Trim 17
Restrike & Pierce
Big Press 1
Deburr
Sanding Belt 3
Fig. Cell-Family B
A02505A0004 A02505A0036 A02505A0006 A02505A0035
Demand = 3.94%
TRIM 16
A01484A0001 A01775A0001
Demand = 2.96%
Fig. Cell-Family C
CURRENT STATE
Fig. VSM of current state
Fig. Spaghetti chart
Reduce Work in Process (WIP) and Inventory
Reduce waiting time between stations
Reduce transportation using Kanban system
Mixed or dedicated cells to avoid setups
Multi skilled processes – flexible.
Standard work in cell – Avoid contamination
Use of all machines
Fig. Proposed layout