June 15, 2016

Work Breakdown Structure - M-6

Identify the tasks to be carried out

A. Scope

A vast number of activities need to be implemented to deliver a product, as well as human resources, financial capacity and technical resources.

For rational and effective organisation, the tasks for the delivery of the product and its subassemblies should be identified and described in a unique way; the responsibilities concerning them should be clearly determined.

This approach is achieved through the development of the Work Breakdown Structure (WBS).

The WBS is based on the RNC document "RNC-CNES-M-HB-10-501 Construction de l'organigramme des Tâches" and "RNC-CNES-M-HB-10-506 Description des tâches et établissement des lots de travaux".

B. Fundamentals

1. Overall considerations

For every element of the functional and/or product breakdown, the tasks to be accomplished should be determined, which quantifies the necessary associated resources and the corresponding schedule (duration and task sequence).

The relevant team, as regards the instrument/experience, identifies precisely the three major types of tasks (non-exhaustive list):

  • Technical:
    • definition of: studies, engineering, analyses,
    • assembly and integration including mock-ups and designs,
    • testing: functional tests, environment, calibration, qualification, etc.,
    • ground facilities: handling, storage and transportation, etc.,
    • operations: use and data processing.
  • Management:
    • cost and deadline management,
    • documentation management,
    • configuration management,
    • monitoring of subassemblies (contract management, reviews, etc.),
    • Interfaces with the next level up (meetings, reviews, etc.).
  • Product Assurance:
    • Quality Assurance,
    • Dependability,
    • EEE,
    • MCP,
    • Software Quality.


For every identified task shall be prepared an activity sheet.

The activities are grouped together in work packages. The Work Breakdown Structure is built up from all the work packages.

2. Activity sheet contents

2.1 Activity characterisation

Each activity is identified in a unique way and is set over time.

It is characterised by:

  • one (or more) supply(-ies), product and/or document, which shows its achievment;
  • identified "input" and "output" (interfaces with the other activities);
  • a clearly identifiable "start" event and a clearly identifiable "finish" event;
  • the allocation to a single entity: individual, laboratory, manufacturer (a person in charge).


It may be identified by a project code, for example "code for the product tree / mock-up / activity type / chronological number.".

2.2 Activity Description

The activity description is performed through an activity sheet which indicates:

  • the relevant phase,
  • the title of the activity,
  • the expected duration,
  • the person in charge,
  • the necessary input,
  • the description of the corresponding work,
  • the output (expected results and supplies),
  • the necessary resources (human and/or material and/or financial resources),
  • excluded activities.


3. Drawing up the work breakdown structure

The Work Breakdown Structure is made of the hierachical representation of the work package sheets.

The Work Breakdown Structure forms the structure of the project's schedule.



RisksComplex international cooperation outline
Multiple interfaces
Project organisation note
Product Tree
Task Flowchart
RisksAbsence of contractual relationships between operators
Memorandum Of Understanding (MOU)
Task flowchart


Activities / documentation

Published in: