But how are you going to get all those people singing from the same hymnsheet, and in harmony?
Have a single unifying plan. 'You don't want to have one integration plan for HR, one for finance, another for systems and yet another for sales,' says Angus Knowles-Cutler, who leads Deloitte Touche's merg- er integration services. 'You need a single, top-down integration plan covering everything.' In a small-scale integration there are more than 15,000 decisions to be made, he adds. Identify the 10 or so the chief exec needs to make so everyone else can get on.
Be straight. Spell out whether this is a merger of equals or an unequal takeover, says John Beedham, European head of Towers Perrin's change implementation business. 'You need to build trust in the new company if you want to keep people with you. The best way is by being honest.'
Don't procrastinate. Selections for key roles need to be made early. 'Good staffing decisions made fast are better than perfect staffing decisions made later,' says Beedham. 'If you hesitate, you create a vacuum.'
Ensure the best person wins. 'Have a fair and transparent process for putting names in boxes,' says Knowles-Cutler. 'Colour blindness' avoids the perception of a winning and a losing side. External consultants can give the process credibility.
Identify leaders and laggards. In a typical integration, says Knowles-Cutler, 10% make it happen, 80% help the integration or watch it happen, and 10% stop it happening. 'You need to know what gets the "middles" off the fence. Work with the stoppers to understand their reservations.'
Vive la difference. Don't whitewash the cultural differences; seek to identify them. Cultural assessment data can be extremely helpful in formulating your communications, says Beedham. 'You need to know if people are used to interpreting messages in a certain way. Both sides need to have an open, expressive dialogue about how they are used to doing things, then openly agree how they will do things together.'
Sort employee benefits later. It's usually impossible to get employment terms and conditions, rewards and benefits packages all aligned on day one. Tell people the timeline for sorting this out. Picking the best benefits from each legacy organisation can be an expensive option; a move to flexible benefits lets people retain what they value most without inflating the cost.
Love thy neighbour. Encourage bonding. 'One of the first things you can do is to physically mix the teams so they are sitting beside each other,' says Knowles-Cutler. Get people jointly working on the business in the marketplace.
Do say: 'This is the structure of our new company and these are the people who are going to lead it.'
Don't say: 'It's all up in the air. Just carry on until you're told differently.'