In general, an inland navigation lock has a structural lifespan of about 100 years, while in most cases this lock is not big enough anymore after 25 - 50 years. This is caused by the growing ship dimensions and/or intensities. A functional flexible lock is the solution for extending the functional lifespan. This type of lock is, with or without a few structural adjustments, capable of serving the shipping traffic for its whole structural lifespan. This design approach will be applied on the lock complex ‘Sluis Sambeek’, which is located in the Meuse route. The first part of the study is carried out on the basis of the Life Cycle Management (LCM) approach. The LCM is started with a trend forecast, from which follows that the future ship sizes are normative for the required lock dimensions. After that, three alternatives are elaborated: 1. Zero-alternative: renovation of the lock. 2. Functional flexible lock: standard lock that is built large enough at once. 3. Structural flexible lock: a relatively easy extendable navigation lock. The maximum dimensions are reached stepwise. Alternative 2 appears to be the least expensive option for ‘Sluis Sambeek’. Although alternative 3 is the most expensive option, this alternative is elaborated further, because it is the most innovative option and could be a better solution for another lock reconstruction. The structural flexibility in alternative 3 is formed by the lock chamber which exists of relatively simple replaceable sheet pile walls, and by floatable lock heads that can be replaced by wider lock heads. The construction planning and the structural lock head design are the innovative parts that are elaborated most specifically. It is concluded that it is useful to consider both the possibilities of a functional and a structural flexible lock design for ‘Sluis Sambeek’ or for another lock location.