Cross-examination of Solid Energy chief executive Don Elder will resume then.
The company has pleaded guilty to three prosecutions under health and safety legislation during his 11 years as its chief executive, he says.
Unless those three factors were "fully and systematically" addressed, the safety risk level at the mine would have been raised to unacceptable levels, he says.
"A common driver of organisational problems is the pressure felt by groups or individuals in the organisation to achieve specific results when they do not have control over all the factors that contribute to the result."
He is explaining Solid Energy's approach to risk management.
He says the difficult conditions of West Coast coal fields require high quality drill holes at an aerial density of no less than 100m of spacing on average.
That compares to an average borehole spacing of 500m in the feasibility study for the Pike River coal mine, he says.
"The level of geological and coal resource information work presented at feasibility study level, would not have come close to satisfying Solid Energy's requirements."
Solid Energy bought a 100 per cent ownership stake in the West Coast mine in 2002. It then placed the mine on "care and maintenance" while extra drilling and investigation of the mining environment was completed.
That extra work would not have been possible if the company did not have other sources of income, Mr Elder says.
"It is a defining difference between the risk profiles of different companies whether they have other cashflow."
"We believed the commercial risk associated with the Pike River development was very high."
He says he was aware of the challenges Pike River Coal faced setting up the mine and had insight into whether their projections would be achieved.
Families expect to hear of 'negligence'
Lax mine safety standards will be revealed as an underlying cause of a deadly explosion at the Pike River mine in the first days of a Royal Commission on the disaster, families say.
Lawyers, family, media and mine officials have gathered in Greymouth this morning for the start of the commission of inquiry.
It was ordered less than a month after the first of a series of explosions ripped through the West Coast mine on November 19, killing the 29 miners and contractors working inside.
The first stage beginning this morning will look at the context of the disaster - with a focus on New Zealand's regulatory environment and the geography, approval and development of the Pike River mine.
Laurie Drew, who lost his 21-year-old son Zen Drew in the disaster, said he expected to hear about "negligence" from Government and mine officials in the coming days.
Questions would be raised over the lack of an alternate entrance to the Pike River mine, he said.
He also pointed to concerns over the fact there was only one mine inspector in the South Island at the time of the disaster.
"It will show there was negligence on the Government's part because they didn't have checks in place.
"This goes further than contractors. This starts from the top down."
Mr Drew said he wanted answers on what led to the explosions which killed his son - if only to stop another disaster happening in future.
But he was more concerned with getting Zen's body out of the mine.
"I'd rather see my boy home than all the stuff that are going on.
"I know my son's waiting for them to rescue him."
Grey District mayor Tony Kokshoorn told Newstalk ZB the first phase will reveal enough evidence to get to the cause of the explosions.
He said it was an opportunity to get to the bottom of what happened and assure future miners that lessons have been learnt.
The decision to ditch the New Zealand mine safety inspectorate in the 1990s would be closely examined, along with the fact Pike River only had a single entrance, he said.
Prime Minister John Key recently told media Pike River would have been illegal in Australia.
Families' spokesman Bernie Monk, who lost his miner son Michael, earlier said he hoped the commission would find out the truth so the tragedy would not be repeated.
He said New Zealand had failed to learn from similar mine disasters overseas and he hoped the commission would not make the same mistake again.
"There is going to be a change in mining in New Zealand because of Pike River and all this must come out in the Royal Commission," Mr Monk said.
While he would have liked the commission to have been able to get into the mine, he was still confident the commission would reach the truth.
"I'm very impressed with the people in charge of the commission and that they are going to do their upmost to get the truth for us."
He said the families would be well represented throughout the hearings and would meet daily.
While the families had been told what was likely to come up during the proceedings, Mr Monk said he was still concerned the commission could reveal "heart-breaking" information which they did not know about.By Hayden Donnell Email Hayden