Introduction

Integration is the unification of the objects through their interactions of energy, matter and information to provide system level functionalities and performances. Integration is a collaborative, value enhancing approach to demonstrating functionalities and performances of products and services. Integration requires the structures of knowledge, the benefit of information, and meaningful data to determine the alternative ways in which to integrate a product and service. Integration requires a clear understanding of the dynamics at the interfaces between objects. An interface is within the boundary that separate two objects or two processes. Physical connection of two objects results in an interface. Functions occur at the interface between two objects.^[1]

Crossrail is accountable for the overall delivery, programme management, design, construction, testing, handover, trial running and completion of the Crossrail Programme. The company is responsible for delivering an integrated and assured Central Section Railway including end-to-end interface works with Network Rail and all other relevant works. It is also responsible for integrating all the assurance evidence of the end-to-end railway in order to demonstrate that all works delivered by both CRL and its Industry Partners are fully integrated and the performance will meet the Sponsors’ requirements and support acceptance by the relevant Operators. Crossrail appoints competent designers and contractors to design and build the Central Operating Section. It is also responsible for accepting both the designs and built assets with the technical assurance evidence necessary to assure that it complies with the Sponsor’s Requirements.

Crossrail have established an assurance approach whereby the aggregated outputs are tested against the four pillars of technical assurance:

• Verify that the railway is collectively safe
• Verify that the railway is collectively maintainable
• Verify that the railway is collectively operable
• Verify that the railway will collectively perform to required levels of capability

Technical Authority is responsible for assuring that all CRL works comply with the Technical Assurance Plan. The Chief Engineers Group (CEG) is the Technical Authority for Crossrail. CEG consists of the following work disciplines: Civil and Structural Engineering, Construction, Architecture, Geotechnical, Mechanical Electrical and Public Health, Route Systems, Signalling, Bulk Power, Communications and Control, Human Factors.

CEG controls the overall engineering assurance process. It is the final acceptance body that provides overall completion certification for the Crossrail Central Section including its end-to-end interfaces works with the other Industry partners such as London Underground, Rail for London, Dockland Light Rail and Network Rail. The CEG review body is independent of the delivery group. This assures that the technical compliance of the Works with the sponsor’s requirements can be verified under least influence by project budget and programme constraints.

The contract strategy for the construction of stations, portals, shafts and tunnels works is that discrete construction work packages for are assigned to design build contractors. The work packages are demarcated by geographical boundaries. Railway system contracts are awarded on a line wide system by system basis. It is therefore of great importance that the packages are fully co-ordinated and integrated so that Crossrail will perform as a single integrated entity meeting all functional requirements even though they are designed and constructed under different work packages. Figure 1 below shows how the systems integration activities by the contractors interact with the CEG.

Figure 1 – Interaction matrix on systems integration activities

CEG has adopted a vertical integration assurance approach to accept, review and control technical and integration elements of the work packages.

Figure 2 at the end of the paper shows the process flow diagram to achieve integration of systems for Crossrail. All procedures, work plans and delivery schedules developed are to support the process flow. The contractors are expected to implement internal work processes to ensure that the component parts that make up the Crossrail rail system operate in a functionally correct manner across system interfaces and that they are coordinated at the interface.

This paper highlights the collaborative approach that Crossrail adopted to manage integration of engineering services for stations, shafts and portals.

Abbreviations

The Collaborative Approach

CEG works hand in hand with the railway systems team, project delivery team and contractors to integrate engineering services at the design, construction, T&C and handover stages. Key areas of focus are integration design control, a common integration database, interface management and integration tests.

Role of CEG

Design

An Engineering Design Assurance Gates procedure is adopted to provide progressive assurance during the design stage to confirm that the objectives of the project will be achieved and that the project can progress successfully to the next stage. The procedure covers a regime where agreed products and deliverables are submitted, reviewed and accepted. In the event that submissions are rejected the Assurance Gates provide a control mechanism for re-submission; and to provide clear visibility at progress checkpoints to ensure compliance to CRL’s broader governance and authority processes. At Gate Reviews, Crossrail seeks evidence that the Systems Integration processes have been correctly followed and that the Design Reviews have taken place and any issues raised have been closed out.

In the Design Phase, specific systems integration related documents to be presented by the contractors for review by the Crossrail are Interface Control Documents, record of interfaces with framework suppliers (e.g. Lifts & Escalators, Building Management System etc.), Systems Integration Management Plan, Testing & Commissioning Plan/Strategy, Systems Breakdown structure and identification, Systems Commissioning Lots structure and identifications, RAM Demonstration Plan, Human Factors Plan, Electro-mechanical Compatibility (EMC) Plan, Evidence of compliance with Crossrail Functional Requirements, Room Data Sheets, Engineering Safety Management Report, Systems Architecture, Alarms Strategy / Matrix, SCADA I/O List, BMS I/O List.

The review is to ensure that they deliver a completed, compliant, co-ordinated, and integrated design. CEG maintains record of reviews in the eB database management system. The latter system also contains a computer based Work Order and VAP (design stage) modules to facilitate centralized management of the business processes.

Construction

CEG provides technical support to the field supervisors to ensure that integration issues are identified, addressed in a timely manner. Some of these issues are details of interfaces, configuration control, RAM reviews and change control. VAP(systems integration- construction) has also proved to be an important tools to ascertain that system integration process is being implemented effectively, in particular in confirming that construction related integration evidence are captured and integration tests are being developed for execution upon completion of work. CEG also liaise with field engineers to identify Hold Points in the Inspection and Test Plans (ITP). The integration surveillance work by CEG targets high risk items in the unlikely event that the final deliverables are not fully integrated. Upon completion of installation work and before commissioning CEG will liaise with field engineers to ensure that plant and equipment is installed in accordance with the assured design, including space for access, maintenance, replacement etc. On material compliance control, CEG will collaborate with field engineers to ensure that all plant and equipment procured / installed is in accordance with the material compliance review procedures. Sample review equipment suppliers manufacturing and shop drawings, installation drawings and standard details are carried out. The review process includes review red-line and as-built drawings, final design, raise and close-out non-conformance reports, and generate VAP Reports to support the incremental acceptance of works leading into Handover.

Testing and Commissioning

CEG monitors the contractor’ systems integration work through progress reviews of T&C work against completeness of documentation, review of T&C test reports, witness integration tests,

Handover

Prior to contract handover, CEG will check that the completed work is in accordance with the final design, review of as built drawings, three dimensional Building Information Management (BIM) computer model, asset tagging and red-lines drawings; review of contractor’s Operation and Maintenance manuals and Verification and Validation reports; review of Handover Packages; review of ESM and Safety related files and justifications, and check for completeness of systems integration deliverables.

In the project handover phase, Crossrail will consolidate the systems assurance records from the contactors and confirm that the railway is fully integrated and fit for operation. CEG will also confirm that the content of the handover packs are suitable for the purpose.

Role of Contractors

At the design stage, the contractors have to produce evidence of design integration timely and in a quality manner.

At the construction and T&C stages, the contractor will provide evidence, in progressive manner, that the deliverables are fully integrated with deliverables of other work packages and systems integrated plan is implemented effectively.

At the contract handover stage, the contractors will provide consolidated technical assurance evidence including compliance certificates, CARE database, Operation & Maintenance Documentation demonstrating that the products delivered are fully co-ordinated, interfaced and integrated.

Responsibilities Matrix

It is important to carry out systems integration works in a co-ordinated manner with a clear roles and responsibilities. The following matrix outlines the role of CEG and contractors in specific systems integration work tasks.

Table 1: Responsibility Matrix- Systems Integration

Configuration Management at Interfaces

In Crossrail, there are situations where performance of safety or mission critical functions requires action of engineering systems constructed under different work packages. To allow concerted action of these systems, effective information transfer via the designated nodal points at the physical boundary between the systems has to take place. Interface nodal point is the location(s) where transfer of energy, matter or information from one system to another will take place in order to achieve a set of meta-system functions in which all the component systems participate. In the context of stations, shafts and portals, the information transfer refers to passage of control and monitoring data between MEP installations and Railway System installations / framework suppliers/ third party installations at the interface panel at the designated plant rooms. Table 2 provides a generic list of the key interface nodal points for MEP installation at stations, shafts and portals. The actual list of interface nodal points is provided in the Combined Services Drawings/ System Architecture Diagrams developed by the contractors.

Table 2: Interface nodal points for mission or safety critical systems

An early understanding of the interface details at the construction stage is essential to reduce the occurrence of integration problems at the testing and commissioning stage. Furthermore, a clear picture of protocols for interface nodal points facilitates technical configuration control on the hardware and software for the interfacing systems and verification activities while managing the systems integration process.

Details of interface nodal points are captured in the systems integration database in a structured manner to ensure there is a line wide consistency on keeping interface information. The list of technical information for the key interface nodal points for stations, shafts and portals is shown in Table 3.

Table 3: Technical Information related to Interface Nodal Points

Integration Tests

Integration Tests are the key verification and validation activities to demonstrate successful integration of the railway functional elements. Table 4 provides an illustration of some of the integration tests to be carried out for the stations, shafts and portals to satisfy the technical assurance requirements with respect to integration of the various services for the areas. It is not an exhaustive list and does not include all integration tests that will be carried out for the stations shafts and portals.

Table 4: Examples of Integration Test for Stations Shafts and Portals

Crossrail Assurance Reporting Environment (CARE)

All Systems Integration and Assurance evidence generated through the contractors are recorded in the CARE database. The relevant information is recorded onto CARE database at the appropriate locations as per the CARE Systems Breakdown Structure. This evidence will support during the Handover and progressive acceptance of Systems and finally for Assets at each location.
The format and level of details of documentation presented by the contractors to demonstrate compliance with systems integration requirements are described in the contractors’ Verification &Validation Plan. They are in the form of independent checks, type test reports, field tests, integration tests etc. Table 5 provides a summary of information to be provided by the contractors to demonstrate that a robust systems integration programme has been implemented.
All systems integration work information related to the effective implementation of systems integration activities are captured in the eB system in Crossrail (an electronic information system).

References

[1] Gary O. Langford, Engineering Systems Integration- Theory, Matrices and Methods, CRC Press, 2012

Table 5:Summary of information related to Systems Integration

 Figure 2: Process Flow Diagram for Systems Integration Activities at Crossrail Stations Shafts and Portals