ISO/TS 22375:2018

TECHNICAL ISO/TS
SPECIFICATION 22375
First edition
2018-10
Security and resilience — Guidelines
for complexity assessment process
Sécurité et résilience — Lignes directrices relatives au processus
d’évaluation de la complexité
Reference number
ISO/TS 22375:2018(E)
©
ISO 2018

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ISO/TS 22375:2018(E)

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ISO/TS 22375:2018(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles . 1
5 Preliminary assessment process . 2
5.1 General . 2
5.2 Mandate and commitment . 2
5.3 Needs and expectations of interested parties . 2
5.4 Embedding competence and awareness. 2
6 Planning the assessment process . 3
6.1 General . 3
6.2 Defining the scope . 3
6.3 Determining the objectives . 3
6.4 Establishing the external context . 4
6.5 Establishing the internal context . 4
6.6 Establishing resource requirements . 4
6.6.1 General. 4
6.6.2 Personnel . 4
6.6.3 Procedure . 5
6.6.4 Method . 5
6.6.5 Communication . 5
6.6.6 Documentation . 5
7 Implementing the assessment process . 6
7.1 General . 6
7.2 Assessment process . 6
8 Monitoring and review . 6
Annex A (informative) List of potential parameters that drive complexity .8
Annex B (informative) Examples of how to carry out the complexity assessment process .12
Bibliography .28
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ISO/TS 22375:2018(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
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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).
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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 292, Security and resilience.
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/TS 22375:2018(E)

Introduction
Complexity is a fundamental property of many systems. An appropriate level of complexity is required
for systems operation, but a high degree of complexity can weaken the system, particularly during
turbulent times. High system complexity could be an obstacle to the security, resilience, effectiveness
and efficiency of all organizations. As organizational systems, products, processes, technologies,
organizational structures and contracts become more complex, organizations may fail to pay sufficient
attention to the introduction and proliferation of more complex and less secure systems that then
become unsustainable and lose their integrity. Figure 1 explains where the introduction of complexity
can improve performance, but where, after it reaches certain point, it will degrade performance. Point
A is the best ratio between performance and complexity.
Figure 1 — The impact of complexity against performance
Organizational complexity cannot be increased indefinitely, however. If complexity exceeds a
manageable level, e.g. interdependencies expand to the degree that all elements are connected with
one another, the system behaviour turns chaotic. Hence, the relationship between organizational
[16]
complexity and performance is hypothesized to be inversely u-shaped, as shown in Figure 1 .
The complexity of an organization’s system is influenced by external and internal factors, often linked
to direct or indirect actions carried out by different parties.
Day-to-day managerial decisions about the organization’s activities tend to generate complexity.
For large companies with decentralized decision-making, decisions tend to be made without the
assessment of complexity cost and benefit trade-offs.
These decisions could add complexity without creating customer or competitive benefits and could
increase the organization’s vulnerability.
Moreover, the decisions taken by customers, competitors and suppliers, as well as the enactment of new
regulations, induce the organizations to adapt themselves to new scenarios. Increasing the complexity
of the external environment may induce the organization to increase the number of functional units
and this could increase functional and structural complexity of the organization.
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Functional complexity is characterized by its management system and its business processes set out in
directives, procedures and reports.
Structural complexity deals with the variety of elements and relationships among the people, products
and services, and assets of the organization.
To assess the complexity of an organization’s system, it is necessary to take into account a large number
of parameters where the interactions change and develop dynamically and in a non-linear laws.
This is particularly true in the context of a turbulent and interdependent global economy, punctuated by
shocks and instabilities of increasing intensity and frequency, which can undermine the performance
and survival of any system.
High complexity is an important source of a new form of risk called “complexity-related risk” that
organizations have to address and manage if the security and resilience of its system are to be sustained.
This document aims to stimulate organizations to take into account the threat created by an excess
of complexity and to consider complexity assessment as an integral part of their plan for security
management.
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TECHNICAL SPECIFICATION ISO/TS 22375:2018(E)
Security and resilience — Guidelines for complexity
assessment process
1 Scope
This document gives guidelines for the application of principles and a process for a complexity
assessment of an organization’s systems to improve security and resilience. A complexity assessment
process allows an organization to identify potential hidden vulnerabilities of its system and to provide
an early indication of risk resulting from complexity.
This document is generic and applicable to all sizes and types of organization systems, such as critical
assets, strategic networks, supply chains, industrial plants, community infrastructures, banks and
business companies.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 22300, Security and resilience — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 22300 and the following 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
complexity
condition of an organizational system with many diverse and autonomous but interrelated and
interdependent components or parts where those parts interact with each other and with external
elements in multiple end non-linear ways
Note 1 to entry: Complexity is the characteristic of a system where behaviour cannot be determined only as the
sum of individual variables behaviours.
3.2
parameter
specific value describing the measurable or theoretical features of the elements of a system
4 Principles
To carry out complexity assessment process effectively, an organization should adopt and apply the
principles below.
a) Complexity is a fundamental property of many organization’s systems. An appropriate level of
complexity is required for systems operations.
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b) High complexity could be a source of a new form of risk called “complexity-related risk”. Complexity
is often an important cause of vulnerability and should be managed.
c) The complexity assessment process should inform the security management process and the risks
management process. It helps the organization to enhance the security and resilience of its system.
d) A complex system has numerous components and interconnections, interactions or
interdependences that may be difficult to describe, understand, predict, manage, design and change.
The complexity assessment process aims to identify the most important process/parameters that
contribute to making the system vulnerable.
e) A complexity assessment process enhances an organization’s resilience and creates strategic and
tactical advantages. It assists the organization to decide how to reduce the variability/volatility of
the parameters to achieve these benefits.
5 Preliminary assessment process
5.1 General
The preliminary assessment process for the complexity assessment process provides the foundations,
structures and capabilities that enable the process to be applied and to ensure its consistent application.
5.2 Mandate and commitment
Top management should provide evidence of its commitment to the development and implementation
of the complexity assessment process and to continually improving its effectiveness by:
a) defining and endorsing the organization’s policy for managing the complexity assessment process;
b) determining the objectives consistent with the organization’s policy;
c) ensuring the availability of sufficient resources and reliable data sources;
d) assigning roles, accountabilities and responsibilities at appropriate levels within the organization;
e) establishing an awareness programme to communicate the benefits of the complexity assessment
process to relevant interested parties;
f) ensuring legal and regulatory compliance.
5.3 Needs and expectations of interested parties
The organization should identify all interested parties relevant to managing the complexity assessment
process and should determine their requirements based on their needs and expectations.
The organization should ensure that the requirements of interested parties are considered.
5.4 Embedding competence and awareness
The organization should make the complexity assessment process a core value of the organization and
should ensure the required competence is maintained.
The organization should ensure that any person(s) is (are) competent on the basis of appropriate
education, training or experience, and should retain associated records to provide evidence of the
training.
The organization should identify training needs associated with its security management plan. It
should provide training or take other action to meet these needs, and should retain associated records.
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6 Planning the assessment process
6.1 General
The complexity assessment process should be an integral part of the security management process and
should be tailored to the objectives of the organization.
6.2 Defining the scope
6.2.1 The organization should define the scope of the complexity assessment process that is
appropriate to:
a) its size and nature;
b) its requirements, considering its mission, goals, legal responsibilities, and internal and external
obligations;
c) its operational objectives, products and services, activities and resources.
6.2.2 The scope should include:
a) the goals and objectives of the process;
b) the frequency, depth and breadth of measurement;
c) specific inclusions and exclusions;
d) the complexity assessment structure and methodologies.
6.3 Determining the objectives
6.3.1 The organization should define the objectives of the complexity assessment process in accordance
with the security management process.
6.3.2 The process could be addressed to identify, at least:
a) the structural complexity of the organization;
b) the functional complexity of the organization;
c) the interdependencies between organizational process and functional units;
d) the main parameters connected with the complexity of the system.
6.3.3 These objectives should:
a) be consistent with the scope and policy;
b) be retained as documented information;
c) be clearly stated;
d) have time frames for their achievement;
e) enable opportunities to maintain or improve performance;
f) be monitored and updated as appropriate.
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6.4 Establishing the external context
The organization should identify those areas of the external environment in which it seeks to achieve
its objectives. The external context can include, but is not limited to:
a) the social, cultural, political, legal, regulatory, financial, technological, economic, natural and
competitive environment, whether international, national, regional or local;
b) the external infrastructure on which the organization depends, including the market, utilities,
suppliers, logistics and related processes;
c) key external drivers and trends that impact on the objectives of the organization.
6.5 Establishing the internal context
The organization should identify the factors of the internal environment in which it seeks to achieve its
objectives. The internal context can include, but is not limited to:
a) governance arrangements, including policies, structures, roles and accountabilities, and the
decision-making processes (both formal and informal);
b) personnel and related capabilities;
c) physical assets, technologies and internal infrastructure;
d) capital, financial arrangements and income streams;
e) information systems, reporting and other information flows.
6.6 Establishing resource requirements
6.6.1 General
The organization should allocate sufficient resources to managing each step of the complexity
assessment process. The allocation should consider:
a) funding;
b) trained and competent personnel with the appropriate knowledge, skills and experience;
c) procedures, methods and supporting infrastructure;
d) communication and documentation.
6.6.2 Personnel
6.6.2.1 The organization should:
a) appoint one or more management representatives who, irrespective of other responsibilities,
should have defined roles, responsibilities and authority for ensuring the effectiveness of the
complexity assessment process;
b) identify the skills and knowledge required by those involved in the complexity assessment process;
6.6.2.2 Knowledge requirements include:
a) analytic systems, business intelligence, etc.;
b) organizational processes and functional units of the organization;
c) corporate enterprise resource planning (ERP) or business warehouse systems, and protocols, etc.
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6.6.3 Procedure
The organization should define a specific, flexible and focused procedure to manage the implementation
of the complexity assessment process.
This procedure should define:
a) how the assessment is to be clearly targeted to the organization’s system;
b) the frequency within which assessments are conducted and the intervals between assessments
that are considered to be appropriate by the organization;
c) how the changes since the last assessment are to be determined.
The complexity assessment process may be performed by self-review or on-site review by an external
organization or a combination of both.
6.6.4 Method
The organization should:
a) identify suitable assessment methodologies and/or techniques to identify, analyse and evaluate the
complexity;
b) choose the appropriate qualitative and/or quantitative analytic approach based on the type, size,
or nature of the organization and resource and skill constraints.
NOTE A qualitative approach uses the answers to questionnaires to identify the main causes of increases in
the complexity of the organization’s system.
A quantitative approach uses algorithms to measure the parameters within the ERP to highlight the critical
points of the system or the organization.
6.6.5 Communication
The organization should have effective communication and consultation procedures for the exchange
of information of the complexity assessment process with interested parties.
These should include:
a) internal communication among interested parties, including employees within the organization;
b) external communication with customers, partners and other interested parties, including the media;
c) receiving, documenting and responding to communication from all interested parties.
6.6.6 Documentation
The complexity assessment process documentation should include:
a) policy, scope and objectives;
b) complexity assessment process options;
c) awareness programme;
d) training programme;
e) procedures for implementing the complexity assessment process.
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7 Implementing the assessment process
7.1 General
The main source of complexity in an organizational system is the unpredictable variability of its most
important and interdependent parameters.
These parameters could be identified inside these main fields:
a) size and diversity of products and services;
b) management hierarchy and behaviours;
c) amount of directives, procedures and reports;
d) relationships among the people of functional units;
e) interactions among the operative, support and control processes.
A list of potential parameters that drive complexity is provided in Annex A.
7.2 Assessment process
The complexity assessment process should be managed at three different levels.
a) LEVEL 1: Define complexity environment.
At this level, the organization can identify only the framework of the organizational system in
terms of external and internal complexity fields.
b) LEVEL 2: Qualitative complexity assessment.
If the organization recognizes that the complexity of its organizational system could generate a
risk, it should use methodologies and/or techniques for a qualitative complexity assessment.
The assessment is performed with questionnaires, which should be filled in during suitable
surveys and workshop. Through a set of internal and external parameters, it is possible to compare
the interrelationships among the organizational elements (process, product, organization,
performance, resources, mission etc.) and identify the related complexity fields.
c) LEVEL 3: Quantitative complexity assessment.
If the organization wishes to thoroughly investigate its complexity, it should pass to a quantitative
methodology. It should use algorithms that highlight the critical issues of the organizational system
through the measurement of parameters inside the ERP.
The output is the ranking of each parameter based on its contribution to overall system complexity.
Annex B provides some examples of how to carry out the complexity assessment process.
8 Monitoring and review
8.1 The organization should develop procedures for the systematic monitoring and review of the
performance of the complexity assessment process on a regular basis and at planned intervals.
8.2 Monitoring procedures should:
a) determine the extent to which the organization’s complexity assessment process, objectives and
targets are met and how they impact system performance over the expected range of operating
situations;
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b) assess the performance of the complexity assessment process and procedures after its
implementation;
c) record the data and results of monitoring and measurement to facilitate corrective actions.
8.3 The organization should:
a) review the complexity assessment process at planned intervals to ensure its continuing suitability,
adequacy and effectiveness;
b) use the information obtained from the review to address the need for changes to the scope, policy
and objectives of the complexity assessment process;
c) evaluate the resource allocations of personnel, including employees and contractors, data sources,
procedures and tools;
d) identify changes in the activities, functions and risks that will affect the organizational system,
including changes to:
1) the organization and its processes;
2) suppliers and the supply chain;
3) technology;
4) systems and application software;
5) legal and regulatory requirements;
6) the market sector and the local, national and global economy;
e) consider the lessons learned and the issues identified during the implementation of the complexity
assessment process.
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Annex A
(informative)

List of potential parameters that drive complexity
A.1 General
To assess the complexity of an organization’s system, it is necessary to take into account a large number
of parameters, where interactions change and develop dynamically and in a non-linear ways.
A bibliographic analysis of work on complexity assessment carried out by several authors has identified
a list of potential parameters.
These parameters are divided in two parts: internal and external, depending on whether they belong to
inside or outside the organization.
Subsequently, the parameters have been categorized in accordance with their main reference area.
For more information, see Reference [1].
A.2 Internal parameters
Table A.1 — Internal parameters — Primary processes
Purchasing process Sales process Production process
Quality of bulk materials Number of deliverables Variety of the product components
Material price escalation Combined transportation Interdependence between the
components of the product
Early purchase order Commercial burdens
Number of product groups at
Unfamiliar procurement
production site
Number of suppliers,
Productivity
subcontractors, contractors
Number of production facilities
Quality of suppliers,
subcontractors, contractors
Combined transportation
Commercial burdens
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Table A.2 — Internal parameters —
...