Automated tests have become the most sought after method of testing in today’s market. Automating systems is generally found to be cheaper, faster and more reliable than manually operating them. For this reason many companies decide to make the switch over to this inexpensive yet efficient way of testing, only to realize that their costs have in fact gone up. The reasons for this could be poor planning, automating too much too soon or even automating unnecessary parts of the system. This study takes a closer look at the effects of automating tests used on interlocking systems. A tool has been developed as a part of the automated tests at Bombardier. The main function of the tool is to speed up the testing process by automatically generating test cases rather than having a worker write them down. The aim of this paper is to present this recently developed tool and show how its use significantly reduces testing time, costs and workload compared to the manual tests used today.

Developing software without considering the potential changes it mighthave to undergo in the future can be a costly mistake. This is becauseits maintenance costs can become very expensive as they can consumeover 90% of the total life-cycle costs. Incorporating maintainability insoftware has for this reason become highly attractive since it can significantlyreduce the maintenance costs and therefore save companies andsoftware developers a fortune. This thesis presents a software tool thathas been developed to aid Bombardier in the verification of computerbasedinterlocking (CBI) systems. The tool automatically generates testcases which represent the different tests that verify the interlocking system.The paper is divided into two parts. The first part focuses on themaintainability of the tool while the second part investigates whetherthe tool can speed up the testing process of CBI-systems at Bombardier.The results show that the tool is highly maintainable and that tests onCBI-systems can be performed significantly faster with it. / Att utveckla mjukvara utan hänsyn till de eventuella förändringar somden måste genomgå i framtiden kan bli ett kostsamt misstag. Dettaberor på att dess underhållskostnader kan bli mycket dyra eftersom dekan konsumera över 90% av de totala kostnaderna. Det har därför blivitväldigt attraktivt att lägga fokus på underhållbarhet när man utvecklarmjukvara eftersom det kan avsevärt minska underhållskostnadernaoch därmed spara mjukvaruutvecklare och företag en förmögenhet. Idenna uppsats presenteras ett verktyg som har utvecklats för att hjälpaBombardier med verifiering av datorställverk. Verktyget automatisktgenererar testfall som representerar de olika testen som verifierar ställverket.Uppsatsen är uppdelad i två delar. Den första delen fokuserarpå verktygets underhållbarhet medan den andra delen undersöker omverktyget kan påskynda testprocessen för datorställverk på Bombardier.Resultaten visar att verktyget är väldigt underhållbart och att