Descriptors of service granularity Sharing Common Functionalities Joni Karanka, ONS

Context All initiatives that deal with sharing services across institutions have to deal with service granularity However, we do not currently have good descriptors of granularity to support sharing

Uses of granularity descriptors Across NSIs, descriptions of statistical service granularity can be used for: Describe services in the service catalogue for adopting organisations to assess the service Support the scoping of service development Support the development of policies around service identification, development and sharing

The granularity model 2 dimensions: granularity and cohesion Granularity uses GSBPM to describe the functional level the statistical service supports Cohesion describes how closely the service aligns with the GSBPM functional level it supports

Granularity Cohesion Description in GSBPM Level of phase (level 1) Very coarse Service contains a full GSBPM phase (e.g., dissemination) Service contains related activities of more than one phase (e.g., design and dissemination of metadata) Service contains functionality from several phases (e.g., design, collection, management and processing of data) Level of sub-process (level 2) Coarse Service contains a full GSBPM sub-process (e.g., editing and imputation of statistical data) Service contains related activities of more than one phase (e.g., editing and imputation, and related design activities) Service contains unrelated functionality from several sub-processes (e.g., classification, editing, imputation, aggregation and production of outputs) Level of business function (level 3) Fine Service delivers a clearly defined business function below the level of sub-process (e.g., design collection instrument) Service delivers several related business functions from different phases (e.g., design collection instrument, provide collection instrument) Service contains unrelated business functions from several phases (e.g., design collection instrument, provide collection instrument, load data, code data) Level of services or utility services that support a business function Very fine Service delivers a micro or utility service that can support a business function Service delivers several related micro or utility services Service delivers several unrelated micro or utility services Cohesion Fully cohesive Complementary Heterogeneus Fully covers one function at specified granularity Most functionality relates to one function at specified granularity, complemented with functionality from another phase or sub-process Contains functionality from several phases or sub-processes

Fully cohesive, very coarse Level 1 Phase Level 2 Sub-process Level 3 Business function

Heterogeneous, very coarse Level 1 Phase Level 2 Sub-process Level 3 Business function

Complementary, coarse Level 1 Phase Level 2 Sub-process Level 3 Business function

Fully cohesive, fine grained Level 1 Phase Level 2 Sub-process Level 3 Business function

Examples of use Provide clear description of development intention: “we are creating fully cohesive fine grained services, we will provide an interface” Agree policy: “services in the catalogue have to be at least coarse grained and not heterogeneous”