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Planning review and schedule risk assessment


An engineering company had been contracted to prepare a plan and estimate for a coal handling and preparation plant with a view to being engaged to build it as the EPCM contractor. The coal processing equipment itself was to be designed by a specialist subcontractor.


The prospective EPCM contractor and the specialist plant designers, a separate company, needed assistance to confirm when they could commit to delivering the plant. They had a partly developed plan that was framed by major milestone dates but not yet bedded down. They were working with this as they moved towards a contract, using rules of thumb and experience to make sure they were not too far away from reality, and expecting to lock it down when they had agreed the approach with the mine owners.

Services provided

In consultation with the project planner, we prepared a model that was consistent with the key assumptions of the master schedule and embodied the dependencies that would govern progress. The model consisted of about thirty activities representing major blocks of work. This was used to plan an intensive workshop to explore uncertainty in the activity durations and risk drivers affecting the project.

Broadleaf did not set out to critique the work of the project planner but to use analysis and modelling to help the team understand the uncertainty in their plans and estimates. Each major task duration and risk factor, such as the productivity of direct labour, was examined systematically to understand the assumptions upon which the plan was based, the sources of uncertainty around those assumptions, pessimistic and optimistic scenarios that might arise and a quantitative assessment of the range of possible values the duration or risk factor might take on.

The approach used by Broadleaf to explore these uncertainties minimised bias from optimism, anchoring and other sources. It produced a concise informative description of the risk associated with the plan that not only explained the uncertainties but also provided a starting point for later reviews and updates.


Serious concerns about the master schedule came to light in the workshop and actions were assigned to rectify them. In addition, important questions were raised about the quality of some of the information upon which the plans and estimates were based. Critical disconnects between the prime contractor and the specialist engineering design team were exposed. These and various other concerns had not come to the attention of the business manager prior to the workshop.

The availability of the labour force that it had been assumed would implement the work was called into question. Productivity assumptions in the plan were based on using crews who had recent experience in constructing a nearby plant that was almost identical. It emerged that their work was running late and they might not be free when required for this job. It became apparent that the mine owner’s expectations about the completion dates would have to be adjusted.

The master schedule was reviewed after the workshop to take account of the uncertainties expressed in the model and other matters that came to light. By the time the analysis was complete the project team had reached a point in their own minds where they understood what had to be done to put the plan on a sound footing and the effect this would have on a reliable end date. What they believed about the project was reflected in the model and the model could be used to support their judgment and make a persuasive case for the revised delivery timetable.

A large engineering services company
Mining and minerals processing
Services included:
Schedule uncertainty
Quantitative modelling