VSM

 VSM Objectives and Associated KPI VSM(Value Stream Mapping) is a

technique that aims to identify and eliminate waste throughout the
system, minimize resources used, and optimize organizational
performance. It also acts as a proactive tool for analyzing and selecting
technological approaches right from the start of a project

 Work in Progress (WIP) refers to the inventory between the start and end
points of a process. Lead Time is the total period a customer waits to
receive a product after placing an order. If demand exceeds the system’s
capacity, the waiting time increases beyond the production time
In terms of KPI, there is Takt time, calculated as available time divided by
demand :

 Process cycle efficiency (PCE)Takt time =the

compares (Available Time)/Demand
value-added time (VA)
with the total cycle time (Lead Time). A process is considered Lean if
the value-added time is more than 25% of the total cycle time
PCE=VA/LT
 VSM consists of three main sections
• Process or production flow: Shows the flow of materials throughout the
production process.
• Communication or information flow: Identifies all communication within
the value stream.
• Timeline and distance traveled: Represents the execution time of the
process, the total cycle time, and the physical distance traveled by the
product or people within the process.
 To effectively apply Value Stream Mapping (VSM), four main
steps are followed

1. Product or Product Family Selection: A product or product family

with common processing steps and equipment is chosen.
2. Drawing the Current State Representation: A map is created representing
the current state of the value stream, identifying and mapping each step
of the process from raw materials to the final product.

3. Value Stream Design (VSD): Once the current state is understood, the desired
future state is designed, eliminating inefficiencies and developing an optimized
model. This process aims to create a clear and improved vision of the value
stream. It explores Takt time, continuous flow, pull systems, production
scheduling, and process improvements to optimize operational efficiency and
effectively meet customer demands.
Strategic questions :
• What is the Takt time, considering the available labor time?
• Should you produce for finished goods stock or directly for dispatch?
• Where should you implement continuous flow?
• Where should you introduce pull systems with supermarkets?
• Where should you plan production in the production chain?
• How should you level the production mix in the pulling process?
• What increment of work will be released evenly by the pulling process?
• What process improvements are needed to guarantee the flow of value according to the
future state of the project?
 4. Drawing up a Work Plan to Achieve the Future State: A detailed work plan is
defined to implement the proposed improvements, covering the actions
needed to move from the current state to the future state, with clearly
defined responsibilities

 Case Study :
• This company, specializing in metalworking and making items like jewelry and
metal accessories, started in a garage with just 12 workers. Over time, it grew by
adding new services such as machining, polishing, and galvanization. In 2013, it
adopted its current name and focused on expanding its production processes. By
2016, the company acquired another business, bringing the workforce to 80
employees. The company has always invested in new machinery and employee
training to stay competitive. Its goal is to manage the entire production process in
Portugal, from start to finish. This ongoing investment has helped the company
grow and stay innovative in the industry.
 Selection of the Product
• Family
To create the Value Stream Mapping (VSM), the first step was selecting the product family,
and Bracelet was chosen due to its high order volume. This family includes different
versions of the product with variations like stem length, hole configuration, and semicircle
diameter. Bracelet is a semi-finished product, made up of components like Ecrou(Nut) and
Pontet(Bracket or Guard), along with other parts assembled and delivered to the customer.
The process began with observing and understanding various production areas to get a full
picture of the workflow. A batch of Product E was tracked from machining to shipment.
Since the polishing process is outsourced, it was simulated in this analysis.
 Productive Process and
• Flow
The manufacturing process for Bracelet begins with receiving stamped pieces from a
group company and issuing a machining order. The pieces are moved to the
machining area for CNC processing, then inspected and stored in the control stock.
Logistics transport the batch to an external company for polishing, which involves
multiple steps like preparation, washing, and polishing. After polishing, the batch
returns for the addition of the Ecrou component and is partially assembled. Next, the
product undergoes galvanoplasty, including a bath and inspection. Logistics then
assemble the final product with other parts in the kit. The kits are inspected before
being sent to the shipping area for delivery. The product flow is depicted in a
spaghetti diagram.
Processes
Process Flow

Reception Pre - assembly

Shipping

Machining
Galvanoplasty

Polishing Final
Assembly
Data Collection and Analysis
• setup time, cycle time, available time, and actual
operation time
• table was created with timed metrics (second/
piece; minute/piece;
hour/piece; minute/lot; hour/lot; and day/lot).
• Uptime, Takt time, and PCE/efficiency were
calculated
 Analysis
 Reception
• Reception The process starts with material reception, which takes about 3 days
for stamping and 120 h for delivery.
• In this activity add necessary value (VA) are material reception and order
issuance (4.5 h/batch), while non-value-added activities (NVA) total 120.5 h per
 Machining
batch

• The machining area consists of three machine sets named B, H, and C. Material
processing is performed on CNC machines in set B (machines B4, B5, and B6). Each
CNC machine has a rotating panel that performs specific operations in sequence.
• The first operation (cycle time: 3 min and 14 s)
• The second operation (cycle time: 2 min and 50 s)
• Quality control is supposed to be hourly but is impacted by time spent cleaning
burrs.
• Cleaning burrs causes unplanned stops and reduces availability to 78% (5.75
hours).
• Setup time is 3 hours, varying with adjustments and tuner availability.
• Stock waits 40 minutes before transport to the polishing unit.
• The planned time per shift is 7.33 h with a daily demand of 110 pieces (55 per
 Polishing
• Product E, initial preparation (Lapidage) takes 80 s per piece.
Following Lapidage, the batch is transported for washing (29 min),
semi-automatic polishing (33 min per pass, with 2 passes), and
further washing and waiting. Manual polishing follows (95 s per piece)
and final washing before quality control.
• Efficiency is 45%, with transport and waiting times being significant.
Activities adding value total 5.36 h, and non-value-added activities
total 6.67 h, resulting in a 12 h Lead Time
 Pre -
assembly
• Product E requires pre-assembly before precious metal deposition. Logistics
transports the polished pieces for pre-assembly, where an Ecrou is partially
added (32 min for 50 pieces, 15 s per piece). Following pre-assembly, the
batch waits (33 min) before logistics transports it to galvanoplasty. In this
process the VA is 0.53 h, with 4.81 h of NVA, resulting in 10% efficiency.
 Galvanoplasty
• The batch is mounted on Bouclards for a series of ultrasonic,
degreasing, activation, and plating baths (0.97 h total)
• The total VA time is 1.89 h, and the NVA is 10.96 h, with a significant
wait for plated components that need to be assembled into the main
product. Efficiency is 15%.

 Final Assembly
• Final assembly involves visual inspection, complete Ecrou insertion,
and Pontet attachment (75 s per piece). The batch is checked,
kitted, and prepared for shipping. Total VA time is 6.33 h, with
various waiting times reducing efficiency
 Shipping
• Upon reaching shipping, the batch undergoes final quality checks
and kit verification (10 min), is declared in the management
software, packaged (1.5 min), and shipped (30 h to the customer).
VA activities total 21.17 h, and NVA activities total 315.17 h,
resulting in a Lead Time of 367 h and a cycle efficiency of 6.29%.
 Current VSM
 Improvement
• The main problem identified was in final assembly, where the current cycle time exceeds
the Takt time; it is essential to reduce the cycle time to match customer demand. The
most appropriate approach is to maintain the push flow in machining but create a pull
system between electroplating and final assembly. In addition, it is proposed to
implement a Kanban system to control the stock of final products.
 Machining

• To identify opportunities for optimization, the setup process was

monitored and timed. The setup consists of 10 operations.

• The setup process was observed to involve mostly internal activities, except for the first-
part validation. A waiting time of about 1 hour was identified due to tuner unavailability
and shift changes. Some internal steps, such as tool preparation, can be externalized
during production by using SMED mechanisms. Recommendations include installing tool
shelves and utilizing machines to expedite tool changeover, reducing internal setup
time from 3 hours to 2 hours and 40 minutes.
 Polishing
• In the production of E, each batch of 50 units requires four sandpaper changes,
totalling 36 min per day. Adopting self-adhesive sandpaper reduced the
changeover time to 51 s, saving 15.6 min a day and resulting in monthly
savings of 327.6 min, representing a time reduction of 43%. monthly saving of
around EUR 3 per operator and glue booth.

 The most significant proposed improvement involves changing the

production flow and layout between the assembly and galvanoplasty
sections.
 To enhance efficiency in assembly and galvanoplasty, a layout reorganization
is proposed to establish a continuous flow between the two areas,
eliminating non-value-adding activities like transport and waiting. Key
actions include implementing a Kanban production system, creating shelves
for pre-assembly, and introducing a pull-type system to optimize the value
flow. Logistical steps will be reduced, stock created between areas, and a
conveyor system introduced to ensure FIFO during electroplating. Walls
between sections will be removed to facilitate connection, and final
assembly will be grouped with control. These Lean Manufacturing-inspired
changes aim to streamline production, reduce waste, and improve overall
Future VSM
The current state was characterized by
(1) Lead Time: 336.45 h
(2) value-added time: 21.17 h
(3) process cycle efficiency (PCE): 6.29%.

 After implementing
• SMED reduced setup times by 20 min.
• Self-adhesive sandpaper reduced unnecessary movements by 0.04 h.
• The most significant improvement was the restructuring of the layout and
flows, with the creation of component stock, which eliminated approximately
14 h of non-value added (NVA) time.
 The new state improved the process by
achieving:
(1) Lead Time: 318.14 h
(2) value added time: 22.75 h
(3) PCE: 7.15%.