  When planning a survey for astronomical transients, many factors such as
cadence, filter choice, sky coverage, and depth of observations need to be
balanced in order to optimize the scientific gain of the survey. Here we
present a software package called $\texttt{simsurvey}$ for simulating the
supernova lightcurves that are expected based on a survey strategy, which can
then be used to determine the potential for discoveries of each strategy in
question. The code is set up in a modular fashion that allows easy modification
of small details of the survey and enables the user to adapt it to any survey
design and transient template that they wish to use in planning their survey.
As an example of its utility, we use $\texttt{simsurvey}$ to simulate the
lightcurve of several types of supernovae that the recently started Zwicky
Transient Facility (ZTF) is expected to find and compare the results to the
discoveries made during its early operations. We conclude that ZTF will find
thousands of bright supernovae per year, of which about 10 could potentially be
found with two days of explosion. Over the course of three years the survey
will obtain lightcurves of about 1800 type Ia supernovae with $z < 0.1$ that
can be used as distance indicators in cosmology if they are spectroscopically
classified using additional telescopes. In a comparison to detections from the
ZTF public survey, we found good agreement with the numbers of detections
expected from the simulations.
