In any mechanical manufacturing industry, raw materials' cost is the major cost component which constitutes up to 40% of the total cost. Other major cost is the processing cost to convert the raw materials in to a finished product that takes place in an assembly line. Optimizing the available resources including the number of work benches and operators is important to meet the timely delivery of finished goods with optimum cost. In an assembly line, the manufacturing processes on any material are sub-divided into many tasks which may include sub-assemblies and machining. These tasks are carried out in several work stations which are responsible for a single or a set of operations carried out on the materials. Assembly lines need to be balanced to have even distribution of work for both men and machines. Type 1 simple assembly line balancing problems (SALBP-1) refer to minimization of number of work stations by keeping the cycle time constant. If the number of work stations is fixed, minimizing the cycle time falls under Type II problems. To solve these types of NP-hard problems, heuristics are used by researchers. The heuristics use different parameters to assign a particular task to a work station. This paper proposes and analyses a few heuristics that can be used to solve SALBP-1. They use slope indices to order the jobs and assign them to different work stations. The slope indices are the ratios of any two parameters taken suitably © 2019 Elsevier Ltd.