Value stream management (VSM)

This document provides guidelines for the application of VSM with regard to the collection, evaluation and continuous improvement of value stream relevant data. In addition, it describes the assessment of value streams based on defined key performance indicators. The VSM method described in this document is generally applicable to material‑, energy- or data‑related process types. In practice, there are often hybrid forms of these main process types.

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Status
Published
Publication Date
08-Mar-2020
Current Stage
6060 - International Standard published
Start Date
09-Mar-2020
Due Date
20-Apr-2020
Completion Date
09-Mar-2020
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ISO 22468:2020 - Value stream management (VSM)
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INTERNATIONAL ISO
STANDARD 22468
First edition
2020-03
Value stream management (VSM)
Reference number
ISO 22468:2020(E)
©
ISO 2020

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ISO 22468:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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ISO 22468:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Value stream management . 2
4.1 Basic VSM procedure . 2
4.2 Value stream analysis . 3
4.2.1 General. 3
4.2.2 Selection of a product family . 3
4.2.3 Data collection . 4
4.2.4 Analysis of the current state . 4
4.3 Value stream design . 5
4.3.1 General. 5
4.3.2 Improvement potentials . 5
4.3.3 Orientation towards an ideal state . 5
4.3.4 Design of a future state . 5
4.4 Value stream planning . 5
4.4.1 General. 5
4.4.2 Catalogue of measures for improvement . 6
4.4.3 Workshop on value stream plan . 6
4.4.4 Implementation . 6
4.5 Assessment of value streams . 6
4.5.1 General. 6
4.5.2 Value stream performance indicators and assessment concepts . 6
4.6 Adjustment of value streams . 7
4.6.1 General. 7
4.6.2 Actions for continuous improvement . 7
Annex A (normative) References for the application of VSM . 8
Annex B (informative) Data boxes and application examples .17
Bibliography .33
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ISO 22468:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 154, Processes, data elements and
documents in commerce, industry and administration.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO 22468:2020(E)

Introduction
The value stream management (VSM) method is an effective tool for the collection, evaluation and
continuous improvement of product and information flows within organizations. The VSM methodology
includes the analysis, design and planning of value streams. In consideration of an ideal state, the
current state of the value stream is mapped according to the gathered data and subsequently analyzed
to design a future state with less waste and a reduced lead time. Based on a variety of different VSM
approaches, which have been developed in the framework of Lean Production primarily since the
1990s, there are communication and collaboration issues during the application of VSM in practice
due to different value stream visualizations and associated calculation procedures. In particular,
these challenges occur at the interfaces of departments, corporate groups or entire supply chains (see
Figure 1). Therefore, the adherence of rules and guidelines in regard to VSM is required to ensure a
common and standardized method for the collection, evaluation and continuous improvement of value
streams within cross-enterprise value networks.
Figure 1 — Communication issues at supply chain interface
This common and goal-oriented application of VSM leads to a reduction or elimination of waste,
e.g. unnecessary discussions or the multiple and thus redundant preparation of value stream data
targeted to each contact person or auditor are omitted.
With the help of a defined procedure in terms of a unique VSM method, value streams of different
sectors and process types are holistically improved. In addition, consistent product and information
flows based on a unified VSM method enable a coordinated process planning (see Figure 2).
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ISO 22468:2020(E)

Figure 2 — Integrated supply chain
A common understanding of value streams enables organizations to streamline their internal and
external processes. In this regard, the standardized VSM method ensures a unified collection,
visualization and calculation of value streams, first within companies or corporations and
consequentially along supply chains.
All information or requirements within this document can be transferred to any process type. Figure 3
[2]
shows a suitable scheme for the structuring of different process types .
Figure 3 — Main process types
The downstream-oriented product flow in Figure 2 can be generated by material-, energy- or
data-related processes. The material- or energy-related processes can be further separated in manual
or automated processes of either single, series or mass production. The data-related processes comprise
service, trade or management processes.
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INTERNATIONAL STANDARD ISO 22468:2020(E)
Value stream management (VSM)
1 Scope
This document provides guidelines for the application of VSM with regard to the collection, evaluation
and continuous improvement of value stream relevant data. In addition, it describes the assessment of
value streams based on defined key performance indicators.
The VSM method described in this document is generally applicable to material-, energy- or data-related
process types. In practice, there are often hybrid forms of these main process types.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
batch size
number of jointly processed (semi-finished) products
3.2
bottleneck
most heavily loaded process (step) in terms of capacity, which is dynamically changing
3.3
continuous improvement
identification of improvement potentials in the sense of a continuous improvement process (CIP) in
small steps
3.4
control-ticket
internal purchase requisition, which is used for product flow control (e.g. card, box or electronic)
3.5
customer takt
time interval, which corresponds to the operating time in relation to the (expected) customer demand
per period under review
Note 1 to entry: Customer takt is expressed in time unit per piece.
3.6
lead time
time period from the date of order receipt to the transfer of the product to the end customer
3.7
pacemaker process
process step, which sets the pace for the overall process flow
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3.8
product family
group of product variants, which require identical or similar process steps
Note 1 to entry: Within this document the term “product” can be understood as material-, energy- or data-related.
3.9
push system
control of product flow based on upstream processes
3.10
pull system
control of product flow based on downstream processes
3.11
range of inventory
time period, which corresponds to the current inventory levels in stock and warehouse
3.12
relative value stream performance indicator
comparative key performance indicator for the assessment of the future state in consideration of the
current state of the value stream (3.14), in contrast to absolute value stream performance indicators
3.13
supermarket
central instrument with regard to pull systems (3.10), which enables a demand-oriented withdrawal
3.14
value stream
all processes oriented at customer demand, that is in particular product and information flows
3.15
value stream mapping
method to develop the current state map of product and information flows within organizations
Note 1 to entry: Value stream mapping is one step of the overall procedure VSM.
3.16
work in process
WIP
total stock level or total range of released starting products and (semi-finished) products within
considered value stream (3.14), which are either in process or waiting for further processing
4 Value stream management
4.1 Basic VSM procedure
Figure 4 shows the basic procedure of VSM.
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ISO 22468:2020(E)

Figure 4 — Basic VSM procedure
The basic VSM procedure can be divided into three main phases: value stream analysis, value stream
design and value stream planning. After the selection of a representative product family, relevant data
is collected in regard to the current state of the value stream. Based on this current state, concepts for
the identification of improvement potentials such as continuous improvement are applied, which lead
under consideration of an ideal state as guidance to the desired future state. The individual suggestions
for improvement are documented in a catalogue of measures for improvement. Subsequently, this value
stream plan is discussed with the responsible employees and implemented within the organization.
These three phases are part of the PDCA (plan-do-check-act) cycle, as they cover “plan” and “do”.
Referring to ISO 9001, the first eight steps cover “plan” and the last step, the implementation itself covers
“do”. The two missing phases, “check” and “act” are only possible at a later time, since they require a
monitoring and an adjustment of the implemented changes. Therefore, they are not included within the
basic VSM procedure, but carried out later. In order to conclude the PDCA cycle, an assessment of the
value stream is carried out (check), which compares the previous with the target state. The last part
covers individual adjustments (act) of the operating value stream to guarantee a stable proceeding.
Following this procedure, continuous improvement is ensured by using the PDCA cycle as a frame of
reference.
In 4.2 to 4.4, the different phases will be elaborated in detail.
4.2 Value stream analysis
4.2.1 General
The value stream analysis phase is divided into three fundamental steps, which are specified in 4.2.2
to 4.2.4.
4.2.2 Selection of a product family
First, a product family needs to be selected to reduce the complexity of the subsequent steps to collect
data as well as to analyze the current state. This product family shall have the following characteristics:
— identical or similar process steps and associated product variants;
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ISO 22468:2020(E)

— representative product of the organization, with strategic or economic importance;
— preferably balanced sales, order or processing volume, no or small takt time variations.
4.2.3 Data collection
For the selected product family, a subsequent collection of value stream relevant data is performed as
a second step of the value stream analysis phase (see A.3 for parameters and calculation procedures).
For this, i.a. data originating from interviews with process participants, measured or estimated values
as well as system data needs to be captured and processed for the later analysis of the current state.
A selection of relevant parameters for particular process types is listed in Annex A and Annex B.
4.2.4 Analysis of the current state
Based on the selected product family, the current state of the value stream is analyzed. For this purpose,
the captured parameters are mapped comprehensively in form of a value stream map, which shall be in
accordance with Annex A. Figure 5 shows the typical setup of a value stream map.
Key
information flow
material flow
Figure 5 — Typical setup of a value stream map, current state
Since the VSM method is oriented to the needs of the end customer, the symbol for the end customer
(A.2) is placed first in the right upper part of the value stream map and associated parameters (A.3)
are gathered. Then, the external product flow to the end customer is depicted. Subsequently, the actual
process flow with associated data boxes (B.1) and the external process flow from the suppliers, which
are illustrated with a supplier symbol in the left upper part of the value stream map, are captured.
Furthermore, the information flow among customers, suppliers and processes as well as the process
planning and control is visualized. Finally, a value stream assessment based on criteria like lead time
(bottom line in Figure 5), costs or resource consumption is performed.
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A combination of the typical value stream map (Figure 5) with flowchart elements or swim lane
diagrams can be advantageous for example in case of data-related process types to illustrate the
detailed process sequence or to clarify responsibilities (see an application example in B.4).
4.3 Value stream design
4.3.1 General
The value stream design phase can be divided into three steps: the identification of improvement
potentials, the definition of an ideal state as guidance as well as the design of a future state.
4.3.2 Improvement potentials
[3]
In consideration of the 7 types of waste , the goal of value stream design is to reduce or eliminate
deficits with regard to the product and information flow, which have been identified during the value
stream analysis phase. Based on the gathered value stream data of the current state, suggestions for a
subsequent implementation of improvements in terms of a CIP are collected and documented, e.g. these
suggestions for improvement are displayed as continuous improvement flashes in the value stream
map, which shall be in accordance with Annex A.
4.3.3 Orientation towards an ideal state
As a second step of the value stream design phase, an envisaged but practically not achievable ideal
state is defined as guidance. This ideal state represents a perfect, waste-free process flow, which can be
carried out in minimal lead time.
4.3.4 Design of a future state
[4]
By means of the ideal value stream and under consideration of the following guidelines , an improved
future state as compared to the current state is developed. The value stream map of the future state
shall be in accordance with Annex A.
— takt time at the pacemaker process;
— supermarket or direct shipping;
— continuous product flow;
— supermarket pull systems;
— definition of pacemaker process;
— levelling of product mix at the pacemaker process;
— release of products at the pacemaker process;
— further process improvements in terms of a CIP.
During the design of a future state also the collected potentials or developed suggestions need to be
considered for the continuous improvement of the value stream. This future state is to be pursued
subsequently.
4.4 Value stream planning
4.4.1 General
The value stream planning phase comprises a collection of improvement suggestions in form of a
catalogue of measures to achieve the envisaged future state, a cross-departmental workshop with the
responsible employees as well as the implementation of the previously discussed measures.
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4.4.2 Catalogue of measures for improvement
For the documentation of improvement suggestions, a catalogue of improvement measures for defining,
limiting and linking the actions to responsibilities is suitable. With regard to the detailed definition
of individual measures, the so-called SMART method shall be applied, so that individual goals are
[5]
"specific, measurable, accepted, realistic, and time-related ". In addition, the status of implementation
of the different measures or actions shall be noted.
4.4.3 Workshop on value stream plan
Subsequently, the compiled catalogue of measures shall be communicated to the responsible employees
within the organization and, if required, internally discussed. This allows identifying and addressing
risks of the suggested changes and accordingly concludes “plan”.
4.4.4 Implementation
Based on the agreement, the determined measures are implemented within the organization in the
context of a CIP. This step deals with the realization of what was planned and complies with “do”.
4.5 Assessment of value streams
4.5.1 General
For the assessment of value streams, the following key performance indicators and assessment
concepts are suitable (see A.3 for parameters, calculation procedures and example). In addition, a later
monitoring of the changed value stream is required. Thus, this function corresponds to “check”.
4.5.2 Value stream performance indicators and assessment concepts
Relative value stream performance indicators provide an analysis with regard to the performance of the
future or target state in comparison with the current or actual state of the value stream (indices ACT
and TAR). Thus, to assess value-adding and non-value-adding value stream shares, the following KPIs
for a relative assessment of (non-) value adding shares (VAS and NVAS) from a customer perspective
shall be determined.
TOTAL lead time: tt=∑ +∑t
LT PT IT
ACTUAL value adding share:
t
PTACT
S =
VAACT
t
LTACT
ACTUAL non-value adding share: t
ITACT
S =
NVAACT
t
LTACT
TARGET value adding share:
t
PTTAR
S =
VATAR
t
LTTAR
TARGET non-value adding share: t
ITTAR
S =
NVATAR
t
LTTAR
Based on the determined value stream performance indicators, relative comparison indicators (ω ,
PT
ω , ω ) shall be conducted to assess the benefit of the future state in contrast to the current state.
IT LT
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Key comparison figure process time:
t
PTTAR
ω =
PT
t
PTACT
Key comparison figure idle time: t
ITTAR
ω =
IT
t
ITACT
Key comparison figure lead time:
tt+
PTTARITTAR
ωω= =×SS+×ω
LT VAACTPTNVAACTIT
tt+
PTACTITACT
Also an analysis with regard to multiple assessment criteria, beyond the pure consideration of lead
time, is useful in some applications of VSM. In this context, a value stream assessment based on criteria
like space requirements, resource consumption or costs can be performed (see Reference [6] p. 156 ff.).
Furthermore, a cost-benefit analysis for the assessment of costs and benefits of suggestions for
improvement provides a means to get a quantitative analysis with regard to the advantageousness of
individual improvement measures. The improvement measures shall be prioritized according to the
result of the cost-benefit analysis and subsequently considered and implemented within the process.
In addition to the assessment of the value stream, it is important to monitor the modified value stream
over time to detect weaknesses. This helps to determine if all the planned activities are working as
expected and to see if any of them has negative impacts on any other areas.
4.6 Adjustment of value streams
4.6.1 General
After a successful assessment and monitoring of the modified value stream, it is important to take
actions to further improve the performance and adjust detected inconveniences. Doing so, “act” of the
PDCA cycle is as well covered.
4.6.2 Actions for continuous improvement
Based on the previous assessment and monitoring of the modified value stream, it is now possible to
adjust detected weaknesses of the operating processes. It is a repetition of the described VSM procedure
in context of continuous improvement.
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Annex A
(normative)

References for the application of VSM
A.1 General
The selection of value stream symbols (Table A.1), data boxes, parameters (Table A.2) and calculation
procedures are based on a comparison of different existing VSM approaches (see References [4], [6], [7],
[8], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24]).
A.2 Symbols and terminology
Table A.1 — Value stream symbols
Symbols
Additional information/position in value
Category Symbol Term
stream diagram
processes process material-, energy- or data-driven process
differentiation: end customer (symbol customer
customer
process) vs. customer/plant (symbol
processes
process
external sources)
position in value stream diagram: top right
if supplier also customer: use of symbol for customer
supplier
processes process/
process
external source
position in value stream diagram: top left
use of business process for the detailed definition of com-
business
munication means (e.g. telephone, mail, IT system, etc.)
processes process,
if needed, number of operators [number or full-time
indirect area
equivalent (FTE)]
shared
process/
processes process with double framing
shared resourc-
es
number of operators [number or full-time equivalent
(FTE)]
processes operators
position in value stream diagram: within process symbol
define resources for every process type
processes resources (e.g. machines, area, tools, etc.)
position in value stream diagram: within process symbol
(pre-)selection of process parameters, cf. data per
process type
processes data box
position in value stream diagram: within process symbol
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Table A.1 (continued)
Symbols
Additional information/position in value
Category Symbol Term
stream diagram
additional information: number of repetitions
repetitive
processes
process
position in value stream diagram: above process symbol
processes bottleneck position in value stream diagram: above process symbol
push product
product flow product flow controlled by upstream processes
flow
external prod-
product flow shipments, external logistics
uct flow
element of process flow control,
LIFO lane or
product flow
FIFO lane
additional information: process quantity
Just-in-Time
element of process flow control,
delivery or Just-
product flow
in-Sequence
additional information: process quantity
delivery
inventory triangle incl. I for inventory,
product flow stock
additional information: number of products or range
organized warehouse, safety stock,
product flow warehouse
additional information: number of products or range
element of pull system
product flow supermarket (product flow controlled by downstream processes)
additional information: number of products or range
element of pull system
product flow withdrawal
(product flow controlled by downstream processes)
product flow truck transport additional information: delivery frequency
other
additional information: delivery frequency, Microsoft
product flow transport
Visio symbols
...

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