1. Executive summary:

The aim of this assignment is to reinforce the advantaged of logical planning and scheduling of a real engineering project (Middleborough Road Rail separation project completed in 2007). The project consists of four different stages. Those four stages are advanced works, weekend occupation works, major shutdown works and completion works. And there are 50 sub-tasks in those four stages.

The first step is to make the linkage of sub-task in these four stages, also make the estimation of the duration for these sub-tasks and then use Microsoft Project to draw the bar chart. After these work, the critical path will appear.

PERT (program evaluation and review technique) can be used to control and plan the uncertainty of project. Sharma stated that’ considering PERT, and taking possible risk related to each activity into account to acquire a more reliable and realistic time frame. ‘(2006).

The total labour hour for Middleborough Road rail separation project is 234,070, however the work time is different in each stage. The work time for advanced work is equal to 38 hour per week. As for weekend occupation work, there is 60 hours per weekend, which consists of 5 shift per 12 hours. This period will continue for four weekends. During the major shutdown period, there is a 3 shift per 8 hours. For this reason, the work will undertake 24 hours per day.

The last step is resource levelling; this step is to examine the unbalance use of resource and use day-by-day resource levelling to resolve the problem of over-allocations and conflicts. The histogram of resource demand and the result after resource levelling will be shown below to demonstrate the distribution of resource.

2. Introduction:

As mention in assignment 1, Middleborough road is a major road and located in the eastern of Melbourne. This road is one of the busy level crossings on the eastern rail corridor. In order to eliminate the railway level crossing at Middleborough, Vic road implement the Middleborough road project. And this project consists of three parts: Box Hill, Laburnum, and Blackburn.

The purpose of this assignment is to demonstrate a scheduling of project by Microsoft Project. There are 50 sub-tasks in four major stages. After the estimation of duration for each sub-task, a critical path will be obtained. And the explanation and assumption for each work is provided.

However, there is uncertainty and inherent risk of project. Hence, PERT (program evaluation and review technique) should be used to control the uncertainty of project. A network diagram will be provided and the explanation of PERT also will be supplied either.

The total labour hour used for the whole project is equal to 234,070. According to the total cost for labour component and the duration for each stage, the number of labour can be determined. For advanced works, there are 143 workers. As for weekend occupation work, there are 243 works and there are 237 workers for major shutdown works. For completion works, there are 41 workers. Table of labour requirement will be provided below.

In terms of the scheduling and given budget for each stage for Middleborough road project, a histogram for Middleborough road project resource levelling will be provided. Due to the limitation of resources allocated, resources levelling need to be more realistic. For this reason, determining available for resources based on day by day levelling to determine whether the demand histogram is acceptable or not. Then, using resource utilisation factor to evaluate possible alternatives.

Figure ** (DELETE THIS IMAGE)

3. Planning and Scheduling of Project

3.1.1 Initial Critical Path Method:

A key component in all construction projects is the planning and scheduling of the project in order to estimate a delivery time and for labour allocation. One approach for determining project duration as well as network critical paths is the Critical Path Method or CPM. CPM uses a mathematical basis for: scheduling all tasks within a project; determining start and end dates of a project, including durations of sub-tasks and determining the relationship between tasks (Shwartz 2009). An advantage of this method is determining the ‘Critical Path’; which is as defined by Bergantiños and Vidal-Puga (2009) as the tasks within a project which could potentially extend the duration of the project. A feature of this method is the determination the early and late starts and finishes for tasks which are used to compute total float (TF) and free float (FF); TF and FF indicate how much an activity can be delayed without creating a new critical path (Kaufmann and Desbazeille 1969). In terms of CPM, the critical path is the longest path in the network and each task in the critical path has a total float of zero (Kaufmann and Desbazeille 1969).

3.1.2 Sensitivity of critical path:

However, it is not sufficient to only determine the critical path; the sensitivity of the path also needs to be analysed and there are approaches for this. A sensitive network is one where there is a possibility that the critical path will change during the project (van Everbroeck 2015). To determine the sensitivity of a network, the Total tasks of all other slacks needs to be analysed to determine if any of these could cause sensitivity in the network (van Everbroeck 2015). This process was carried out for the Middleborough Road/Rail project and the results are discussed below.

1.1.1 Assumption and Explanation of major activities

Advanced work:

The Advance Works were carried out during a normal 38 hour working week; however, in Microsoft Project the ‘Standard’ calendar uses a 40 hour working week. Thus the adjustments were made to this calendar in order to meet the 38 hour week criteria. The order of works was fairly logical with the design works commencing first; out of all the tasks, the designing did not require any predecessors. However, it is assumed that community consultation would only occur following the design process. Furthermore, the seeking of tenders in this case takes place after community consultation as it is assumed that project would only move forward with community approval.

The rest of the sub-tasks follow in logical order; supply and installation of temporary buildings would only occur after contractors etc. have been finalised and any other construction works follow after materials have been supplied. It is also assumed that the major tasks in this section such as design and temporary works would incur minimum to no delay, hence, durations were kept short. Determining durations ideally should be based on the quantity of work, resources needed etc. however, since such detailed information was not available, using the project timeframes as a guide, as well as the project online record (VICSIG), the durations were estimated. As a result, it was determined that this section of the project would take 221 hrs or 29 days.

Weekend Occupation

Works would be carried out over 4 weekends, starting each weekend at 6pm on Friday evening and ending at 6am on Monday morning allowing the trains to run as normal over the weekdays. The work would be done in 5 shifts, each shift of 12 hours contributing to 240 hours of total work. The major works to be undertaken include relocating the power and signal cables, excavating and stabilizing the trench along the rail corridor, establishing temporary signals for the major shutdown and relocation and construction at Labrunum Street and Middleborough Road. We made assumption that the relocation of power cables along the rail corridor could start once the buildings and utilities services are set up at Whitehorse Reserve, and is followed by installation of temporary signals and excavation works. In the similar manner, relocation of services at Middleborough road would be followed by construction of the pedestrian underpass. As earthworks, foundation works and wall stabilization could go hand in hand, the soil nailing, bored piles and spray concrete are assumed to start with excavation works with a lag of 4 days. The consultation with stakeholders might happen at weekdays, but we have assumed it to be held on weekends two weeks after the initial consultation during Advance works.

Major Shutdown Works

The major shutdown work would be carried out for 26 days working on a 24-hour schedule, with 3 shifts of 8 hours. The major tasks to be undertaken is removal of overhead gantries, excavation of tracks to the required level, construction of rail tracks over the final level, installation of signals, overhead gantries and catenary cables. At the same time, Middleborough road bridge would be constructed and Laburnum Station restructured. The traffic management services would be provided throughout the shutdown including the real time passenger information on the schedule/operation

of extra buses between Box Hill and Blackburn and rescheduling of trains. We assume that Stage 2 earthworks would start off from where Stage 1 earthworks left and likewise for the soil nailing and spray concreting. The provision of drainage and subsequent construction of rail track along the rail corridor would start together with the soil nailing with a lag of 3 days each. The Geotech works i.e laying foundation is assumed to be completed before the construction of abutment and beam installation at Middleborough Road Bridge and construction of platform and other structures at Laburnum Station. The removal of temporary signalling would be followed by the installation of signals for final tracks similar to the removal and installation of power cables and gantry structures. Once the final signalling system is installed and tested, the first test train would run in the new line immediately followed by the notification of passengers about the operation date. The operation of new rail service on the first day and closure of temporary bus service towards the end will mark the completion of major shutdown works.

Completion work:The last step of this project is work completion and it will take 64 days. The advanced calendar still be used and in this period labours will work 38 hours per week.

After the first test on new track & infrastructure in major shutdown period, labours only can start to remove offices and equipment from Whitehouse Reserve. If the test is not finished yet, labours start to remove offices and equipment; the work of test cannot be finished. (IT IS NOT CLEAR) After this process, the reinstatement of facilities at Whitehorse Reserve and the repairmen of local roads will start. And it will take 30days and 15 days separately. Only, the offices and equipment be removed, the work of repair and reinstatement would not disturb and damage others. Also, labours will have enough space to start reinstatement and repair.

The work of reinstate electrical lighting and services in Middleborough Road will start after the reconstruct road pavement and finishes for Middleborough road and Laburnum street, because the electrical lighting and service is necessary in this stage. To complete stairway at Laburnum station can start at the same time with the repair of local roads. These two stages will not be disturbed. The work of complete access stairway and landscaping at Laburnum station only can start after the most work of Laburnum Street has been finished.The site clean-up will start after all most of work finished, because there is no equipment and facilities in site. Also there is no more rubbish will be created. So this work will start after the repairmen of local roads, the reconstruction of road pavement& finish the work of Middleborough and Laburnum Road. After completing the total work of Project Milestone 2.

1.1.2 The Sensitivity of Critical Path：(explain KHARECE AND SMRITI)

1.2 PERT Analysis

1.2.1 Assumption of PERT

In complex projects such as the Middleborough Road/Rail separation, the planning and scheduling of major and critical tasks is essential to: a) determine the expected duration of the project; b) ensure the project doesn’t take longer than expected; c) ensure all stakeholders are engaged and kept content and d) identify critical tasks and paths. There are a number of tools for network analysis and one such tool is the Program Evaluation Review Technique (PERT). This tool involves estimating the

optimal (TO), most likely (TM) and pessimistic (TP) durations for each activity and the resulting PERT value is the minimum duration for the project (Bergantiños & Vidal-Puga 2009). These three terms are briefly outlined in Table # and these are derived and adapted from Miller (1962).

Table #: Description of time estimates used in PERT

Estimate DescriptionOptimistic (TO) The minimum time a task will take; it assumes no potential risks or potential

delays eventuate.Most Likely (TM) The usual time the task would take under normal circumstances; some risk is

considered.Pessimistic (TP) The maximum time a task will take; this is a worst case scenario, in which major

risks e.g. strikes, unexpected ground conditions etc., are assumed to occur.

TO, TM and TP are used to compute the expected duration of each activity and thus the expected duration of the project; the formula is outlined below:

t e=t 0+4 tm+t p

6

Some issues with this approach include the subjective nature of assigning the activity duration estimates; despite this however, the approach it still seen as an effective network analysis and planning and scheduling tool (Bergantiños & Vidal-Puga 2009). Hence, this approach was applied to the Middleborough Road project in order to determine the expected project duration. Additionally, some of the major risks were also incorporated into the PERT analysis and this is described below. In the case of the project, the most likely values were determined from CPM carried out in part one of this report.

Seventeen major risks were identified for this project and risk analysis was conducted using a risk matrix. This is a relatively subjective process and estimates of risk were made as reasonable as possible. In addition some of these risks have a potential to delay works and thus, extend the project duration. Again these possible delays were estimated subjectively as a percentage of increase form moderate duration. Of these risks, twelve of the high and significant consequence risks were chosen these are discussed in the Appendix A. These risks were incorporated into the pessimistic estimates of the PERT analysis by assigning a percentage by which the duration would increase.

Comparison between project duration with consideration of risk and without this risks. PAULINA

Table **

Type Risk % Duration IncreaseModerate 5%-8.9%Significant 9%-20%

High 20%-25%

1.2.2 Diagram of PERT

1.3 Labour requirements

1.3.1 Labour allocation for major activity

The project has already been divided into four parts, and the total labour hour is 234070, which will be divided into four parts. As for advance work period, the work time is every 38-hour per week. As for the weekend occupation works, which start at 6pm Friday and end at 6am Monday, the work time for each weekend is 60 hour and it is consist of 5 shifts every 12 hours. In this step, our group assume that workers who start their work on Friday night will have 3 shifts each weekend, while workers starting on Saturday morning will have 2 shifts each weekend assuming they work 12hrs in a shift in a day. Therefore, on an average, we assumed the shift of this period is equal to 2.5. After weekend occupation work, there is a major shutdown period, this process will continue for 4 weeks. There is a high intensity work during major shutdown period. Although there is more shift work in real life, our group assume that each worker do on shift per day to make the project become easier.

The total labour cost for all time-related task is equal to $46,940,00, and the total labour hours used for the time-related tasks in this project is 234,070. Therefore, the corresponding labour hours for total activity are equal to 200.5.

Table **

Stage Cost Days N°Hrs % Hrs.

ADVANCE WORKS $6,336,900 27 31,599 14% WEEKEND OCCUPATION WORKS Total $11,425,196 46 56,973 24%

MAJOR SHUTDOWN WORKS Total $25,225,556 23 125,789 54%COMPLETION WORKS Total $3,952,348 64 19,709 8%

Total $46,940,000 160 234,070 100%

In the appendix A, the cost of labour component of each stage has already been given. Taking the advance works stage for example, the total cost of labour component is equal to $6,336,900. This was determined using the following equations; first the equation is stated then the it is applied using Advanced Works as an example:

Proportion(COST )=Cost for each−task

Cost forwhole project

Proportion(COST )= 6,336,90046,940,000

=13.5%≈14%

Labour hous formajor activity=Budget given for eachmajor activirtyTotal budget for whole project

×Total labour hours for the project

Labour hous formajor activity=¿ 6,336,90046,940,000

×234,070=31,599

Using equations 1 ad 2 and table ##, there is one 8 hour shift per day for this stage, so the number of

shifts for this stage is 31,5998

=3950.

Required number of workers=Required labour daysduration

The duration of this step is 27 days. Therefore, using equation 5, 143 labours are needed for this phase of the project.

The number of labours in each step can be calculated by the same formula and method. The result of this can be found in Table **Table**

Stage % Hrs. Hrs per Shift Shift per day/weekend

Workers

ADVANCE WORKS 0.14 8 1 143

WEEKEND OCCUPATION WORKS 0.24 12 5 237

MAJOR SHUTDOWN WORKS 0.54 8 3 197

COMPLETION WORKS 0.08 8 1 41

Tasks Predecessors Duration Cost of each task % of total cost No. of hours No. of workers/hr1 ADVANCE WORKS Total = $6,336,900 　 221 $6,336,900 14% 31,599 1431.2 Undertake civil works detailed design 　 56 　 　 4620.3 21

1.3 Undertake signalling works detailed design 　 48 　 　 3960.2 18

1.5 Consult with stakeholders on project benefits and disruption during construction. 2,3 24 　 　 1980.1 9

1.4 Specify, seek tenders & supply rail, overhead gantries, galvanised steelwork & road beams 4 63 　 　 5197.8 24

1.1 Supply & install buildings & services on Whitehorse Reserve (sports ground site) 5 24 　 　 1980.1 9

1.6 Temp Works: Construct passenger transfer facilities at Blackburn Station 6 29 　 　 2392.6 11

1.7 Temp Works: Construct passenger transfer facilities at Box Hill Station 6 29 　 　 2392.6 11

1.8 Construct Laburnum street underpass while trains are still operating 6 56 　 　 4620.3 21

1.9 Construct external station structures while trains are still operating 6 54 　 　 4455.3 20

Total 　 383 　 　 31599 1432 WEEKEND OCCUPATION WORKS Total = $11,425,196 1 240 $11,425,196 24% 56,973 2372.1 Relocate main power & signal cables along edge of rail corridor 6 28 　 　 1726.4 7

2.2 Install temporary signalling system for major shutdown period 12SS+3 days 40 　 　 2466.3 10

2.3 Test & commission temporary signalling system 13 8 　 　 493.3 2

2.4 Stage 1 earthworks excavate sides of lowered trench‐ 12 202 　 　 12455.1 52

2.5 Stage 1 works – Install Soil nails & bored piles 15SS+3 days 180 　 　 11098.6 46

2.6 Stage 1 works – Apply sprayed concrete to hold trench walls. 15SS+3 days 180 　 　 11098.6 46

2.7 Install safety devices for rail track protection each weekend 12SS 68 　 　 4192.8 17

2.8 Relocate utility services at Middleborough road & Laburnum street 9,10 72 　 　 4439.4 18

2.9 Construct Middleborough Road pedestrian underpass 19 27 　 　 1664.8 7

2.10 Consult with stakeholders on arrangements during shutdown period 4FS+15 days 97 　 　 5980.9 25

2.11 Issue notification to passengers of operation date for temporary bus service 21FS+15 days 22 　 　 1356.5 6

Total 　 924 　 　 56973 2373 MAJOR SHUTDOWN WORKS Total = $25,225,556 11 640 $25,225,556 54% 125,789 1973.1 Provide traffic management services during shutdown period 22 640 　 　 21331.5 333.2 Remove overhead power catenary cables 12FS+54 days 72 　 　 2399.8 43.3 Remove gantry structures and track side signal lamps‐ 25SS 72 　 　 2399.8 43.4 Stage 2 earthworks excavate to lower tracks to final level.‐ 15 411 　 　 13698.8 213.5 Stage 2 Geotech works Install soil nails into trench wall to final level‐ 27SS+2 days,16 262 　 　 8732.6 143.6 Stage 2 Apply sprayed concrete to hold trench walls to final level 27SS+2 days,17 262 　 　 8732.6 143.7 Construct abutments and install beams for Middle borough Road Bridge 28,29SS+1 day 64 　 　 2133.2 33.8 Construct platforms & track support at Laburnum Station 28 260 　 　 8665.9 143.9 Construct drainage alongside tracks in lowered trench 28SS+5 days 120 　 　 3999.7 63.10 Construct rail track: sleepers, rail & ballast 32SS+5 days,27 150 　 　 4999.6 83.11 Extra rail operation activities to terminate trains at Box Hill & Blackburn 24SS 98 　 　 3266.4 53.12 Operate temporary bus service between Box Hill & Blackburn 24SS 520 　 　 17331.8 273.13 Rescheduling trains & buses & providing associated real time passenger information‐ 24SS 450 　 　 14998.7 233.14 Install Structures for Overhead traction power cables & Signal Gantries 26 94 　 　 3133.1 53.15 Install overhead catenary cables 37SS+3 days 100 　 　 3333.0 53.16 Remove temporary signalling system used during shutdown 34,13 32 　 　 1066.6 23.17 Install signalling system for final track work configuration. 37,39 72 　 　 2399.8 43.18 Test & commission the final signalling system 40 16 　 　 533.3 13.19 Run first test train on new track & new infrastructure 38,41,33 20 　 　 666.6 13.20 Notify passengers of operation date for new line and closure of temporary bus service 42 35 　 　 1166.6 23.21 Operate first day of new rail service and close bus service. Milestone 1 completion 43 24 　 　 799.9 1

Total 　 3774 $- 　 125789 1974 COMPLETION WORKS Total = $3,952,348 　 486 $3,952,348 8% 19,709 414.1 Remove offices & equipment from Whitehorse Reserve (sports ground) 42FS+5 days 40 　 　 828.1 24.2 Reinstate facilities at Whitehorse Reserve (sports ground) 46 240 　 　 4968.6 10

4.3 Undertake repairs to Local Roads 46 120 　 　 2484.3 54.4 Re construct road pavement & finishes for Middleborough Road & Laburnum Street‐ 48,19,20 160 　 　 3312.4 74.5 Reinstate electrical lighting & services in Middleborough road 49 96 　 　 1987.4 44.6 Complete access Stairway at Laburnum Station 49SS 40 　 　 828.1 24.7 Complete landscaping at Laburnum Station 51 160 　 　 3312.4 74.8 Site Clean up 49,50,52 96 　 　 1987.4 44.9 Completion of total project Milestone 2 completion. Community Opening 53 0 　 　 0.0 -

Total 　 952 $- 　 19709 　

1.1.1 Labour allocation for sub-task

Number of labour required for theask=Expected durationof−activites

∑ of expeted duration for all−activities×number of labours required for−task

TABLE: GENERAL INFORMATION (STAGE, COST,% DURATION ,

1.2 Resources levelling

The goal of resource levelling:

Usually, a successful project not only makes the cost down but also maximum uses their resources. Sometimes, skilled labour, adequate equipment, high quality materials and correct mix also should be taken into consideration. Using the resource allocation tool in Microsoft Project can test the usage of resource for a project is balance or not. If the distribution of resources usage is smooth and the work is continuous without interruptions, this means the project is successful. However, if the demand histogram is not acceptable, reschedule the project is necessary. After modify and reschedule, if the distribution of resource usage become relatively smooth, meanwhile the demand histogram is acceptable. For this reason, the project becomes successful. But, if the distribution of resources is even, it is not realistic. This situation will cause the inefficient use of the labour resource. In terms of the distribution of resources, the project is successful or not can be determine.

Before levelling: RUF= Useable resource× DaysusedUseableresource× Daysavailable

×100%

After levelling: RUF=Useableresource× DaysusedUseableresouce× Daysused

×100%

1.3 Conclusions

1.4 References

Bergantiños, G & Vidal-Puga, J 2009, 'a value for pert problems', International Game Theory Review, 11, 4, pp. 419-436, Business Source Complete, EBSCOhost, viewed 12 October 2015.

Kaufmann, A, & Desbazeille, G 1969, the critical path method; application of the PERT method and its variants to production study programs, n.p.: New York, Gordon and Breach [1969], UNIVERSITY OF MELBOURNE's Catalogue, EBSCOhost, viewed 15 October 2015.

Miller, RW 1962, 'How to Plan and Control with PERT', Harvard Business Review, 40, 2, pp. 93-104, Business Source Complete, EBSCOhost, viewed 13 October 2015.

Shwartz, A 2009, 'Scheduling basics: the CPM approach', Contractor, 6, p. 22, Academic OneFile, EBSCOhost, viewed 13 October 2015.

van Everbroeck, 2015, MS project network sensitivity, Microsoft Project Tutorial, viewed 13 October 2015, <http://www.project-tutorial.com/ms-project-network-sensitivity/>.

http://www.tacticalprojectmanagement.com/network-sensitivity-and-the-critical-path/

Sharma, s.c .2006. Operation research: Pert and CPM and cost analysis. New Delhi: Discovery Publishing House

Yaghoubi, S, Noori, S, Azaron, A, & Fynes, B 2015, 'Resource allocation in multi-class dynamic PERT networks with finite capacity', European Journal Of Operational Research, 247, 3, pp. 879-894, Business Source Complete, EBSCOhost, viewed 12 October 2015.

Annexure A: MATRIX RISK

ConsequenceInsignificant Minor Moderate Major Catastrophic

Workers Safety

Injuries not requiring Medical assistant

First Aid treatment

Serious injury/ Treatment

Multiple serious injuries

HospitalizationDeath

Alliance and Stakeholders

Minor change without impact

Conditions of the contract affect some stakeholders

(minor)

Problems with claims and

relationships

Re-definition Contract and

change management

Contract severely affected.

Dispute with stakeholders

Conditions and duration

Minor delay without impact

Minor delay with minor

impact

Re-scheduling some task,

delayed less than 2 week

Delivery delayed,

Excavation and signaling problems

Timing severely delayed,

Laburnum station cannot open on time

Operation Management

Minor adjustment in

operation without impact

Replace minor suppliers or redesign the

Operation Plan

Inconvenient but not road and rail client

service compromise

Repetitive problems in operation. Clients are annoyed

Service failure. Not operation

Consequence Insignificant Minor Moderate Major CatastrophicLikelihood 1 2 3 4 5Almost Certain E Moderate Significant Significant High HighLikely D Low Moderate Significant Significant HighPossible C Low Moderate Moderate Significant HighUnlikely B Low Moderate Moderate Significant SignificantRare A Low Low Moderate Moderate Significant

LegendH = high risk, detailed research and management required at seniorS = significant risk, senior management attention neededM = moderate risk, management responsibility must be specifiedL = low risk, manage by routine procedures

RiskLikelihoo

d Consequence Management % Duration

IncreaseObjection from municipality & adjacent land-owners to construction impacts. C Moderate Moderate 5%Unforeseen delays during the 4 week close could lengthen the stakeholder disruption period. C Major Significant 10%Lack of space on site for storage causes delays due to slow delivery of materials to site and slow removal of excavation material. D Minor Moderate 5%

Local community strongly objects to 24-hour construction D Major Moderate 5%

Traffic diverted from Middleborough road during the closure causes congestion E Moderate Significant 8%

Traffic congestion in the excavation trench during the 4 week closure delays time-critical activities. C Moderate Moderate 10%Railway signaling design & construction could fall behind schedule and delay the start-up of trains when the rest of the works are completed. C Catastrophic High 17%Rail passengers divert to other transport modes during the 4 week closure because of inconvenience and don’t return. (lost patronage) A Minor Low 2%Breakdown of plant and equipment during the 4 week closure delays time-critical activities. B Moderate Moderate 8%A delay in one critical activity delays all follow-on tasks and extends the closure period. C Catastrophic High 20%

Unexpected events delay the 600,000CM excavation C Catastrophic High 18%

Delivery of materials to the confined site causes delay to time critical activities. C Moderate Moderate 8%

Injury accident caused by falling objects from bridge construction onto railway construction beneath. C Major Significant 8%

The works at Laburnum Station take longer than expected and delay the start of the first train. C Catastrophic High 15%

Wide range of trade activities and special working conditions may bring demarcation disputes between different trades unions and cause delays. B Moderate Moderate 5%The construction of the new Laburnum street bridge was identified as time-critical for the whole project & could delay final station construction. B Catastrophic Significant 8%

Unexpected ground conditions delay the excavation C Catastrophic High 15%