The saying goes; you never get a second chance to make a first impression. This is as true to public speaking as it is to management. There is no more important time in the tenure of a new CEO than in the first 100 days. These 14 odd weeks have such a profound and definitive effect that they can make or break the CEO’s era. During the first 100 days, as the new kid on the block, you are under the spotlight from a myriad of angles; the board, the management, the staff, the clients and shareholders. All these have their own interests sometimes conflicting and as the boss it is your duty to harmonise them into a common purpose. So what is the secret to having the perfect start?1. Pre- plan and pre-learnAbraham Lincoln advises: if given eight hours to cut down a tree, spend the first six hours sharpening your axe. A hundred days seem pretty a short period to make your mark. That is why your first role when you are appointed CEO should be to seek to extend those 100 days. How do you do this you may ask? There is always the period between your appointment and the day you officially take over the new office.I refer to this as the gestation period. Most big companies, unless they are in a crisis, will allow you a healthy gestation period ranging from two weeks to 90 days. Take advantage of this period.This is the time to seek to learn all about your mission ahead. Conduct your intelligence to have as thorough an understanding of the company as you can. Learn the history of the company and its management. Get your regulator’s perspectives of the company. Seek to know a bit of its culture. For big companies, I suggest hiring a PR/research firm to get you some information (at least that is available in the public domain).There is a thin line between research and spying. You should be ethical in your pursuit of information. Information is power and armed with this, you should be able to plan ahead your mission not just for the first 100 days but as well for the company medium and long term strategy as well.2.Seek to first understand, then be understoodIt’s D-day. You have officially started your day one in the big office. My next piece of advice is likely to sound like a contradiction of my first point but it is not. You have some information and intelligence about the company. It is important to be objective about this information and not let it form your grounded preconceptions even before you step in the company. Even where you think you have been an insider and know the company, the moment you get to the top, you will discover there is a lot more you were not aware of.Now that you are in a position to receive first-hand information and intelligence, means that you can collaborate what you may have heard before and learn new issues. You are also likely to appreciate context better and apply your personal perspectives to it. The first five to 10 days therefore should be what I refer to as "period of understanding.” Seek to understand the board members, senior management, clients and shareholders. Understand the corporate culture and the company’s history.Learn the rank and file and learn exactly what you are getting into. Do not be in a hurry to have instant big declarations in your first10 days in office. It is likely to be counterproductive. This is the time to under-promise so that you get the chance to over-deliver later on. Not the other way. 3.Build an instant rapportIt is lonely at the top. Everyone may acts like they are your friend. Yet many at time you may wonder if they are really your friend of just a friend to the title. Your title means you can get things done. You can get promotions and demotions executed. You can make or break people’s careers. You can make shareholders and investors richer or poorer. Your title is powerful. Your role as CEO is not to be a big boss. Your role is to be a big brother or a big sister. Your job is not to be the dispenser of knowledge but actually the pinnacle of wisdom. Chances are that at the onset, your choice as CEO was not a unanimous decision by the board. Sometimes the choice may have caused some criticism and grumblings. Your first role should be to diffuse any tension that may have been there. Make sure you are in good professional books with your board (especially chair). Have open discussions about expectations of how you will best work together and the expected level of communications. Seek to know the strategic thinking of every board member if possible on a personal level. Your board is going to be an important management tool and will help you in your governance. Harmony with the board will be key to your success.Build rapport with senior management and other staff. Understand the key clients and make friends with them. If you are the major mouthpiece of the company, establish that rapport with the media.Ultimately, when your title is stripped away, all we remain with are our family and friends. Converting our colleagues to friends is the single most important decision we likely to ever take.4. After 45 days, start acting and putting your house in orderAfter around six weeks, coupled with your gestation period, you have now probably spent the right amount of time studying the company.Now is the time to start defining the kind of structure you would like the company to take. Do you want to continue with the systems as they are? Discard them completely or get a compromise? Do want to have a new team or simply a new structure? There should be a balance between making key decisions with careful consideration and getting the appropriate timeframe correct.  You don’t want to move too quickly that you get it wrong without absorbing the right information about the organisation. On the other hand, not acting on things when you know you need to, and taking the hits early is also a mistake.  Typically areas where CEOs can drag their heels to act are on HR issues, thinking they can turnaround individuals that they probably can’t and also on not taking any known financial hits early on. This is the time to get your board behind you and have them share and buy into your vision. Get to execute.Ultimately, remember the wise words of the Swahili people, "Siku njema huonekana asubuhi.” Directly translated, you can tell a good day in the morning.Mr Sissey is the CEO, Business Insider Africa.